Product: Debt collection

In XXXX my mother ( XXXX XXXX ) received a bill from XXXX  XXXX XXXX in the amount of {$3100.00} due XX/XX/XXXX showing her as the guarantor which is incorrect as they should have billed me as I am and was an adult at the time and should have been notified of the bill. My mom called and explained that she is not the guarantor and was told by the representatives that a request would be sent to the billing office to have this changed. 
In XXXX she received another bill due XX/XX/XXXX for {$3100.00} still showing her as the guarantor. She called XXXX XXXX at XXXX on XX/XX/XXXX and spoke with XXXX who told her the request had been sent to the billing office and they had to wait for them to change it and it could take some time. She asked for the billing office phone number and was given XXXX XXXX XXXX. She called XX/XX/XXXX and I spoke to XXXX who would not discuss the bill with her and had no information to give and advised that she had to contact XXXX XXXX at XXXX. She decided to wait and give them time to correct the bill and send it to me as I am the patient and an adult. 
By XX/XX/XXXX there was no updated bill received showing me as guarantor, so she called again and spoke to XXXX who sent another request to change to the billing office. In XXXX XXXX XXXX received another bill due XX/XX/XXXX for {$3100.00} still showing her as the guarantor. 
In XXXX she received another bill due XXXX for {$3100.00} still showing her as the guarantor and advising her that this was her final notice before turning over to a collection agency. She called XXXX XXXX at XXXX and spoke to XXXX, she asked for supervisor and explained that she was very frustrated and upset, she was told no supervisor was available so she then asked her to review the notes on the account prior to explaining why she was calling because this was her fourth phone call on the matter which was still unresolved. She refused to read them and at one point laughed at XXXX. XXXX told her that she had perfect credit and had been continuously trying to correct this and that it was not funny. The phone call was unprofessional and unhelpful until at one point, XXXX changed her demeanor and told her that she was going to try to figure out how to correct the guarantor. She put her on hold and when she came back, she said that she had conferred with a coworker and they knew how to change the guarantor and she assured XXXX that it had been done. 
Then, in XXXX XXXX XXXX received a bill from a collection agency- ARstrat XXXX XXXX XXXX XXXX XXXX XXXX TX XXXX XXXX advising her that she owed {$3100.00}. 
XX/XX/XXXX XXXX XXXX called XXXX XXXX at XXXX and spoke with XXXX. She asked her if at any time she had been told that they could not discuss the bill with her, XXXX told her no because she is shown as the guarantor which is incorrect. She advised XXXX to call the billing office at XXXX. XXXX told her of her past contacts and that nothing had been resolved. She apologized and advised XXXX to call the billing office. She told her they had more power to correct the bill and that it really depended on what agent she got on the phone as to the level of help she would get. 
XX/XX/XXXX XXXX XXXX submitted a complaint with the FCPB. 
The only change that occurred is that the debt was switched into my name with the collection agent ARSTRAT and I HAVE NEVER RECEIVED A BILL FOR THIS DEBT FROM XXXX  XXXX XXXX XXXX. 
XX/XX/XXXX both XXXX XXXX and I contacted a patient advocate XXXX at XXXX XXXX XXXX who listened to the issue and said someone would get back to us. As of today, we have not heard back. 
XX/XX/XXXX XXXX XXXX received a call from XXXX at ARSTRAT regarding this debt.