Product: Money transfer, virtual currency, or money service

Sold my RV to a 3rd Party. On XX/XX/XXXX the Third party transferred {$66000.00} to Bank of the West. Once payment of {$66000.00}. was applied, the balance of loan was {$13000.00}. On XX/XX/XXXX, I accidentally made 2 payments of {$13000.00} through my Bank of the West Mobile app. ( immediately one after the other ). When transaction receipts were not produced or sent, I immediately called the Bank of the West to notify them of the error. I was told to call back on XX/XX/XXXX so both transactions could post. Once both transactions hit my account, one was credited to my account on XX/XX/XXXX. On XX/XX/XXXX, I received a letter in the mail stating my loan was paid in full on XX/XX/XXXX and that I would receive my Certificate of Title in approximately 10 working days. On Friday, XX/XX/XXXX, I received another notification in the mail stating my loan was not paid and I still owed {$13000.00} and that the amount of {$13000.00} was credited back to my account. I immediately called Bank of the West explaining that there were 2 payments sent for {$13000.00} and that only one was returned/credited to me leaving them still holding {$13000.00} of my money. On XX/XX/XXXX, I faxed Bank of the West a copy of my bank statement showing them that there were 2 transactions sent to them from my bank and only 1 returned. I also sent them a copy of the letter stating I was paid in full, and letter stating 1 of the funds was returned. On XX/XX/XXXX a work order with Bank of the West was created by XXXX and updated with all the info I had faxed on XX/XX/XXXX. I called back on XX/XX/XXXX to get an update on status of work order. I spoke with XXXX she said nothing had been done as of yet and she was now escalating work order to her Supervisor with updated notes. She said that I was to call back on XX/XX/XXXX as that is when account action was to be completed and that all info could be found in a XXXX XXXX for next agent to locate. I called back on XX/XX/XXXX only to be told by XXXX that she could not see any of my statements or information in file. She also said work order was not completed yet and that they were " behind '' in their department. She also asked if I could again call back on XX/XX/XXXX. When I said no she again put me on hold for at least 30 minutes. When she returned to me she asked if I could call back instead on XX/XX/XXXX and that she was escalating issue. I called back on XX/XX/XXXX and spoke with XXXX. I once again had to repeat the entire situation to her. She once again told me that nothing had been done or addressed with my case and that she was going to request escalation again. She also said that they were actually going to call me back by end of day. I have requested ( twice ) copies of the 2 transactions I made via the mobile app with absolutely no response back. Every single time I call I have to repeat the entire story with the same exact responses given back to me with not bit of forward movement in an effort to fix this situation. They are holding {$13000.00} of my hard earned money during a pandemic hostage with no professional regard for anything. Everything I have sent them clearly shows they have made a posting error on their end and that it immediately needs to be corrected. In the meantime, I am now considered late on my account and this is now affecting my very good credit!