One of the worst service providers, pathetic!!!!!!

I have been a loyal client for more than 10 years and over the past few years their service has gone down to the point where it is totally pathetic. I have issues with the services I'm being charged for after having asked them to stop the services but i am still being billed and the services haven't been cancelled. phone the call centre is also pointless because after explaining the issue they simply say that they are putting me through to another department and the phone is put down in my ear.i have even insisted on speaking to the supervisor or manager but never seem to get anywhere near them. This is pathetic service and i am so frustrated that i want to cancel my contract but the odds of that happening with the service you receive from them is probably very slim