IQ Data International keeps calling me about a debt that my ex, XXXX XXXX, owes on an apartment that was in his name on the lease. They also say that XXXX paid {$600.00} to have this removed from his name, but then when I call back to confirm, they say that they have never talked to XXXX. XXXX also says they have never contacted him. I advised them they need to contact XXXX about this, but it is now showing on my credit report. Also, the XXXX time they contacted me, they never indicated they were a creditor ( I have had experience with other debt collectors and they always do this ). I also advised that I am going to dispute this and they claimed that I was trying to " evade my debt ''. I have asked for written proof of the amount owed and why the amount has changed each time I talk to them, but they are unable to provide anything in writing. This all sounds very fishy to me and if I am really liable for this debt, I would like to see the proof.