Charged for services I don't require

I was a Nashua Mobile client for many years and was handed over to MTN when Nashua stopped doing mobile.<br> When I reviewed my statement from MTN recently I discovered, that since crossing over to MTN, the Blackberry Internet Service (BIS) has been added to my account. I do not own a Blackberry.<br> <br> I have made contact with MTN via email and received the following reference number - ***9<br> They asked me to give them all my details so they could process the refund.<br> Now that I have done so they say I need to contact the call center. I have tried phoning on many occasions and when I select \0"to be transferred to a consultant the call is dropped.<br> <br> I am owed money that was debited from my account without my authority but can't get hold of anyone to sort it out."""