Is there any sort of law or rule that says I can request all communication with the collection agency to be in writing ( Not that they would listen to the law anyway ). I'm just wondering if this is a reasonable, and legal request to make.

 You can send them a letter instructing them to cease all telephone communications, however, they will still call you regardless. For instance, If the letter is issued by a lawyer, the provincial ministry, myself, or the instruction given by the lender, then the agency must cease and desist all communication providing there is something productive taking place. If it is just because you do not want to talk to the collector - and are not making any effort to resolve the issue per their standards (for whichever reason), then they will contact you regardless. For instance, a lawyer's letter of direction must accompany activity to resolve the problem. Otherwise, there are no grounds.