What to do if they Ticket you?

Here is a guideline as to what to do if you are ticketed by this questionable company:

• Do not under any uncertain terms pay the ticket.  How do they know some prankster didn't remove it - in other words show that the owner of the said vehicle received the said ticket.
• Do not contact them by phone, or email (They've been know to sell private info) or give them any personal information about you whatsoever.  Write them a letter, being as matter fact as possible, asking them to physically prove the violation (photo proof or parking receipt), and don't be cutesy in your letter.  The people taking the calls are running off a script, and don't give a rats ass about what you say.  Send the letter by Registered Letter to their Canadian HQ or Certified letter to their Seattle HQ if you live in the USA.  For example, if you are at a medical office, if they call the office to verify, the medical office has no right whatsoever to disclose any information without your written consent - doing otherwise could lead them amok with privacy laws and the College of Physicians, and similar rules apply to lawyers (solicitor client privilege).
• If they respond to your request, ask them to prove that you were not at the said place of business some time later - some people arrive early for appointments and go across the street for a coffee.  Complain to the manager of the business, and tell them that going forward you refuse to patronize their store if they continue to contract out Diamond Parking, and send a complaint letter to the head office of the company (Some companies actually take this seriously - Safeway and Staples Business Depot for example) - and also complain to the property management company.  Once again, give Diamond Parking as little personal information as possible.
• Wait for the collection letter to arrive - usually it has no return address.  Do not pay it.  Reply to the collection agency stating "The charges that you are billing me for are unauthorized and fraudulent, therefore I am under no uncertain terms going to pay.  You may only contact me by mail at this given address, and I further propose that if you wish to further pursue this matter, you must do so in a court of competent jurisdiction".  Also, in jurisdictions where collection agencies are less regulated where they call you in the middle of the night - and most of the time as a blocked call, set your phone not to accept blocked calls (They will be given a recording "This Number does not accept blocked calls.  If you wish to contact this party, you must press *82 before the number".
• If they further reply, and demand additional fees, check with your local authorities on the legalities, or ask a lawyer.  Complain to the consumer protection authorities in your province/state.  In Canada, you may also ask the RCMP to pursue charges of criminal interest rate.
• Wait for a couple of months to elapse.  Check your credit report, and in all States and Provinces you have the right to make corrections and remove erroneous information.  When a dispute is opened, the said item cannot be held against you, and it is dropped from your credit score.  You simply have to say "The charges were fraudulent, unauthorized, and were the result of deceptive business practices".  The respondent can elect not to respond, or may respond, but you can still put a statement of explanation on your file.  A small amount is unlikely to have much of an effect on your credit rating, and if you have an explanation, many credit grantors will usually be quite reasonable about it.  
• What they can do: the answer is not much.  They can however put your plate number on a watch list and tow away your vehicle if they see it again on one of their lots.  However, I have never heard of this happening - it would be tedious to go manually inputting hundreds of plate numbers, and unless you commit another infraction on the same lot, nothing is going to happen.  To be absolutely certain, go to your DMV, and request a new plate - the fees for replacing lost, stolen, or damaged plates varies from jurisdiction to jurisdiction, but it is far, far less than the ticket.  In the USA, they use the Denver boot in some places, and extort you unless you pay it.  In Canada, individuals can purchase the devices, but only licensed individuals can install them on the vehicle of another (Police, Municipal Bylaw, Campus Security).  
• If your vehicle is towed:  Report your vehicle as stolen.  When you find out where the impound lot is, do not pay cash, pay by credit card only.  When you get your vehicle back, call your credit card issuer within 1 or 2 days.  State that the charges to your credit card were unauthorized and fraudulent.  They will have a chargeback on their hands - and even though they can do something about it, likely it's not worth the trouble for them getting you on a misdemeanor, rather they will try the collection agency.  And to protect your ass, have your lawyer (attorney) send a legal letter to the towing company and the parking company, and demand that they prove they did not tow away your vehicle - in many cases say you went for coffee before an appointment, and then came out of your appointment where you legitimately parked, the judge will likely rule in your favour - there are several legal cases of this nature that have ruled in favour.  It is not too difficult to prove that they are being unreasonable under the circumstances.