Delayed responses to requests all around, no concern for customer satisfaction

My home security and armed response provider was acquired by Fidelity ADT Security. With changes at my residence, I requested technical assistance to resolve some problems with my system and was messed around in many ways. I eventually elected to cancel my services with this provider. However, I noted that I was still debited at the end of September when that was the last month of service. When I queried this, I was advised that this debit order was for September's services, however, I stated that, to my knowledge, my premiums were paid in advance as opposed to in arrears and I requested that a statement of account be provided to me. This request was made 3 weeks ago with follow ups in between and I am yet to receive a statement of account to verify if the last debit order was or was not valid.