Did you ever get your deposit or, in the alternative, an itemized list of why they withheld it?
If you haven't run your credit reports this year, do that and make sure this thing isn't on there.
If you already have run your reports this year or you run them and this thing isn't on them, then send both the collections agency and the apartment complex's management company a letter similar to what gregorio posted including proof of payment. Make sure there is a way to prove the letter was delivered (e.g., priority mail, delivery confirmation, registered mail, etc.). Be very clear in your demand that they provide proof of the debt. [EDIT to add: keep copies of the letters you send.]
If it does show up on your credit report, then read this...
https://forumserver.twoplustwo.com/3...story-1633825/
...and PM me.
Last edited by Rapini; 09-07-2017 at 08:22 AM.