rent payment problem?

Nothing...you have all the evidence you need should they try to take you to court. You did pay by check didn't you?

If I can read between the lines and fill in some details you left out, it sounds like you did not pay by check, or that you paid by cash or money order and did not keep a copy of the receipt.

This is a common mistake people make. Simply being able to show a bank statement where you withdrew $X from your account does not provide evidence of what you actually did with that money.

You need to get with them once more to see if they can look again to find the payment you made. If they can not, you are obligated to pay it "again" and you'll just have to chalk this up as an expensive life lesson.

Make sure you get a receipt from them next time, and keep those for as long as you rent there (and maybe a little longer in case they claim to not have been paid for something after you leave).

let them when you go to court take all the papers and show the judge they won't get it but make sure the bank pay it