R10 ALWAYS BEING TAKEN

For some odd reason, Vodacom keeps telling me the same information but refuse to acknowledge the fact that I am not sending sms's to the 5 digit number that is charging me R10 per sms. They don't know anything about which company it is or how to deregister from the service but they know which number it is. Spoke to Masibuye last night(06/05/2015) at 00h02 and wasn't very helpful, you could swear each consultant i've spoken to has the same script and no one wants to take ownership yet my airtime keeps disappearing. May someone please assist me in rectifying this issue before I port my number because as a loyal VODACOM client I don't expect such from a big service provider to be having such ********** tendencies. All I want is to deregister to the service that I know nothing about, especially since as per Masibuye advised me that I am not registered to anything. Your response and refund will be highly appreciated in regards to this ISSUE!