Americredit Questionable practice of taking insurance repair money Fort Worth, Texas

Worst, uneducated customer service.  "Over-nighted" insurance reimbursement check for their endorsement on Thursday (May 12)  per instructions from customer service - told 72 hours to issue a check back..... Their insurance repair department then asked for final bill before processing the check (as if  had $4k to just pay out of my own pocket)....when presented with the bill from the autobody shop, was told that they needed to verify the work with them first.  Days past by....I calld back to check on the status of the payment, was told they have not received the final bill (despite having a proof of faxing it twice!)....then manager stepped in, told me he would handle the issue personally....got a call Friday (May 20) morning that the repairs were verified and check is being overnighted for Saturday delivery.  In the meantime, body shop called and told me that according to the call they received from the customer service, the check will not be issued until 72 hours from the verification call and they should expect the payment on May 25.  When called back and asked to speak to the manager I initially was dealing with, I was told that he does not accept incoming calls and the nasty woman who claimed to be a manger pretty much told me off....stated that the money was applied to my loan until the check is issued (I also checked that and NOPE, no money was applied).....so long story short....they have  cashed the insurance check on May 16.....holding the cash, earning interest on it.....making up different stories each time just to delay the release .... and my car is at the body shop until they get paid.   My insurance refused to cover the rental car as the work has been completed.   This must be the biggest rip off there is.  How can this be legal??? Wish I could do that.....  and BTW, my loan with them is current....