There is an easy way to get these people to stop calling.
According to the BUSINESS PRACTICES AND CONSUMER PROTECTION ACT;
(4) A collector must not continue to communicate with a debtor
(a) except in writing, if the debtor
(i) $has notified the collector to communicate in writing only, and
(ii) $has provided a mailing address at which the debtor may be contacted,
see this link:
http://www.bclaws.ca/EPLibraries/bcl...eside/04002_09
Simply send the collections agency a fax stating you wish to be contacted by written correspondence ONLY and state the mailing address at which they can send mail to you. Provide your full name and be sure to clearly note what matter pertains to (i.e. parking ticket for license plate number ABC 123) sign the fax, and record the date you sent it. Keep the fax. You also need to send the same fax to the creditor (i.e. the parking lot company such as Diamond Parking).
Also, in the same fax, tell them you wish to dispute the ticket and all related charges in court. They wont take you to court because it's your word against theirs, they won't win. The cost of pursuing the matter in court far exceeds the sum they can hope to recover.
Lastly, a parking ticket and fine from a private parking lot WILL NOT and CAN NOT affect your credit rating. You did not borrow money from them and not pay it back. Parking tickets from the city or a government entity, however, is a different story.