Outstanding balance which is ridiculous

We cancelled our multichoice account telephonically ages ago. We haven't received any calls, emails or letters. Now out of the blue a company calls to say my Mom (pensioner) has been handed over because of an outstanding amount ( +- R250) for not closing her account. This is ludicrous because we cancelled and we haven't used this services in a very long time. It seems as though multichoice is losing clients and is now trying to make money another way. How do you hand someone over when you haven't even told them that there's an outstanding amount owing? Probably because you don't want to hear from the person that your claims are absurd so you pay someone to get the money for you.