Product: Debt collection

In XXXX I received a bill for my adult daughter, XXXX XXXX in the amount of {$3100.00} due XX/XX/XXXX showing me as the guarantor, which is incorrect as I am not the guarantor, the guarantor is XXXX XXXX, my daughter as she is an adult. I called and explained that I am 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 I received another bill due XX/XX/XXXX for {$3100.00} still showing me as the guarantor. I called XXXX XXXX at XXXX on XX/XX/XXXX and spoke with XXXX who told me 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. I asked for the billing office phone number and was given XXXX XXXX XXXX. I called XX/XX/XXXX and I spoke to XXXX who would not discuss with me and had no information to give me and said that I had to contact XXXX XXXX  at XXXX. I decided to wait and give them time to correct the bill. 
By XX/XX/XXXX there was no updated bill received showing XXXX XXXX as guarantor, so I called again and spoke to XXXX who sent another request to change to the billing office. 
In XXXX I received another bill due XX/XX/XXXX for {$3100.00} still showing me as the guarantor. 
In XXXX I received another bill due XXXX for {$3100.00} still showing me as the guarantor and advising me that this was my final notice before turning over to a collection agency. I called XXXX XXXX  at XXXX and spoke to XXXX, I asked for supervisor and explained that I was very frustrated and upset, she told me no supervisor was available and I then asked her to review the notes on my account prior to me explaining why I was calling because this was my fourth phone call on the matter which was still unresolved. She refused to read them and at one point laughed at me. I told her that I had perfect credit and I had been continuously trying to correct this and that it was not funny to me. The phone call was unprofessional and unhelpful until at one point, XXXX changed her demeanor and told me that she was going to try to figure out how to correct the guarantor. She put me 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 me that it had been done. 

In XXXX I received a bill from a collection agency- ARstrat XXXX XXXX XXXX XXXX XXXX XXXX TX XXXX XXXX advising me that I owe {$3100.00}. XX/XX/XXXX I called XXXX XXXX at XXXX and spoke with XXXX. She asked me if at any time I had been told that they could not discuss the bill with me, I told her no because I am shown as the guarantor which is incorrect. She advised me to call the billing office at XXXX, I told her of my past contact and that nothing had been resolved. She apologized and advised me to call the billing office. She told me they had more power to correct the bill and that it really depended on what agent I got on the phone as to the level of help I would get. 
At this point, considering all my attempts I have little faith that this will be resolved and that at some point the collection agency will report negatively to my credit file and try to obtain a judgement against me. I need assistance in getting some resolution and movement with XXXX XXXX.