VODACOM **** TELLESALES ??????

Last year a agent from vodacom call me and offered me a data plan contract for 1gig for R87.00 which I was not interested in because we have wifi at home and at work, she sounded forceful and told me I would save money but I was not really interested, and then told her I need to discuss this matter with my husband just to get her off my back, a month later I checked my bank statement and I see I was billed by vodacom R87.00 for a 1 gig of data which I did not agreed on, I feel really upset about this matter because I did not agreed to this, today I don't trust anyone who calls me from any **** they want to sell me, VODACOM I'M REALLY UNHAPPY ABOUT THIS