Activate sevice on Cell Without notice

Hi - I check my cell regular and saw that a R5 deduction is every day on my cell - When I called Vodacom they told me I am subscribed to a company \DATA SMS SOUTH AFRICA"for a month now without my knowledge. You must call a number *** - This just rings with no answer. How did they get into my phone and deduction just continues. If I did not call Vodacom this will just continue. There must be a way that such deduction must be SMS to trhe subscriber to inform of daily deductions happening. How many is catch by the same company. They must do something about this. John"""