Product: Credit card or prepaid card

On XX/XX/XXXX I noticed that my USAA credit card account was showing as in collections although I had paid off the card days before. I contacted USAA via chat twice that day and realized that I had used an old USAA account number from when I was still married and the funds had therefore been misapplied. I have been with them for over 20 years. 

During the second chat, I uploaded the 4 the Electronic Transmittal Forms ( ETF ) from XXXX XXXX as required by USAA, to prove that I had sent the payments. I not only paid in a timely fashion but I OVERPAID my balance by {$3000.00}. I was told that after I submitted these documents it would take up to 48 hours for them to receive them and there would probably be a 10 business day turnaround. WHY??? I told them exactly where the money went!?? 

Since that time I received telephone calls from their collections department NUMEROUS times although I called back and begged supervisors to make them stop and I kept asking for a status on my issue. No luck. I could list all the dates and times of these calls from collections AND to USAA asking but my phone only retains the dates/times going back to XX/XX/XXXX. 

XX/XX/XXXX I received a call from XXXX in the back office that she had my case but she could not proceed without the account number where the money was sent that SHOULD have been in the original 4 EFT forms but she didnt know why no one mentioned that part of the requirement. Together, we called XXXX XXXX to request these docs and XXXX faxed them to her during the call. It was also during this call that I was informed that when the investigation was complete, the excess money paid would be returned to me via a check in the mail. I asked about the interest accruing on the $ XXXX and she said they would not be paying that to me because this was not their mistake. I asked for the interest because of the amount of time they were taking performing this investigation after I gave them all the information needed on day 1. 
XX/XX/XXXX collections call received XX/XX/XXXX I called to get an update to be told they had not received docs from XXXX XXXX that had been faxed while I was on the phone with USAA and XXXX XXXX on XX/XX/XXXX. This call took 67 minutes. 
XX/XX/XXXX collections call received XX/XX/XXXX Sent message via XXXX to USAA pleading for help. Received response asking for the name on my account and asking for some time for a thorough review of the situation - DC. 
XXXX received an email from XXXX XXXX - Advocacy Advisor stating he would contact me about my issue shortly. Nothing. 
XXXX Asked again through XXXX XXXX. Was told my issues had been shared with the appropriate area. 
XXXX XXXX received ANOTHER CALL FROM COLLECTIONS I've also received mail via US Post about my 'delinquent account ' and the 'investigation ' and my credit card statement amount due has doubled. 

How is it possible that they CAN NOT or WILL NOT resolve this? How much longer are they legally allowed to hold onto my money without a penalty to them and the harassment from their collectors? 

I have attached transcripts of each of my chats with USAA. If necessary, I can provide screenshots to document the calls since XX/XX/XXXX and the email received.