Receiving communication for a number I don't own

I continue to get SMSs from Cell C's system regarding balances for a Cell C number that does not belong to me (I do not have an Cell C contract). I have phoned your support Centre but their response is that there is nothing they can do about it. How is this possible, it is your system that is sending the SMS messages to my phone. I am concerned that someone linked this number to my ID **********ly. I need this resolved asap.