NON END CONTRACT FOR A PENSIONER

I called in to cancel a contract that was due for an upgrade..I wrote a first review, 2 months later I am still getting money that's deducted from my account after speaking to many consultants.. Last month I thought maybe it was a mistake but it went off again. Although the amount has reduced but having money that I don't know it's for what being deducted from my account. i am a pensioner of 10 years with no job. now if vodacom is taking my money for the service i did Not use, is vodacom taking advantage of PENSIONERS?