Being hold hostage by MTN

In October I received a call from them informing me that my children contact is up for renewal,I informed them that I not intrested in renewing it as the service I get from MTN IS PATHETIC!!!. The next day my children informed me there phones is switch of. I left it there as I am not gona get into any legal battle with them,continued paying it as I was planning to cancel it in December when the contract expires,after sitting on the phone for more than 45 minutes listening to the most irritating music ,decided to try again in January since nobody in MTN is working in December.When I phoned today I was informed I cannot cancel because my account is handed over to the Legal department.I was then transferred to the legal department ,just to listen to this irritating music again now for more than an hour