When you stated CIBC informed you that the account was no longer in their hands, first find out if the debt was sold off to CRS. If so, then CRS are going to be the ones who will be responsible for furnishing you with that letter.
Also, if you fail to get anywhere with CIBC's management, ask whoever you are speaking with for the name of their Privacy Officer, along with that person's fax number. You are entitled to receive a copy of this letter, so if you need to play hard ball, we'll teach you how to do it using the powers found within the Personal Information Protection and Electronic Documents Act (PIPEDA)... You'll either hit CRS or CIBC up for a copy of all the information they have on file for you - maybe even both of them?!!? Let's see if they want to play nice, first, ok..
A summary of PIPEDA can be found here:
http://www.priv.gc.ca/information/02_05_d_08_e.cfm
For the the full act:
http://laws.justice.gc.ca/en/ShowFullDoc/cs/P-8.6///en
It's bed time, so I'll have to hold off on any in depth detail tonight. Fill us in on your results tomorrow (uhh. guess that's later today) and we'll go from there.