Vodacom can't explain why they're charging me the service that they already blocked 2 months prior

After I logged a complain about Vodacom,they called me, then the lady who was assisting me can see on her data that my advance options on my account has been blocked, on February, but kept saying the amount I've been charged for on April is for advances, I asked how come because it was blocked on February but you charging on April she end up saying she doesn't know, I must call the finance department to be explained for it, I asked her if the advance is stopped on February and I paid everything in march and you charge it again in April, then tell me when did I take the advance, just tell the date, she says she can't find anything since February...then I told her that her finance department is the one to call me, as I'm not the one on the wrong side....and I won't pay a cent until they resolve my query. Fix my account....Now they have blocked my out going calls but yet deducted R860.87 today....I will dispute it until they treat me with respect