Bad service and dont keep to their word

I have been struggeling to get a debit order instated on my account now for three months due to this my account was in arrears which i then payed in at the bank on saturday morning as per instruction of one of the accounts department ladies. I then when to the Vodacom 4u shop where the sales consultant helped me to do an upgrade which he could not do as the account still showed in arears the consultant phone the accounts department everytime told us that it wil be sorted in 15 min after we faxed through the proof of payment yet again!!! Needless to say after phoning 7/8 times it still wasnt sorted i was told to come back on monday which to no suprize the poor consultant still couldnt help as it still didnt show on your system !!!! this is the upteenth time that i ahve had bad service from vodacom!!! please assist me with this regard