bul**** by vodacom over expired contract

on the 15-10-2015 i cancelled my contract with vodacom. but they conviced me not to cancel and promised to lift my profile to enable me to take the device i wanted. i agreed. .but when i went to the shop to get a new device i was told i could not upgrade on my number because my contract was cancelled and now on prepaid.. they advised me to call accounts and ask them to reactivate my number and put it back to month to month which is where it was before the cancellation so that i can upgrade, i called and asked for that... but to my greatest surprised on the 21-10-2015 i received sms's telling me im now on Uchoose flexi 200 contract and i received 200 airtime. i didnt waste any time i called immediately to ask them to cancel that contract because i did not ask for it. explained that i needed a reactivation so that i can upgrade on the same number and take a new device. i have written emails.called .went to the shop.. till today my problem has not been resolved and they are billing me.. i reversed the debit orders because i know i do not owe them but that is ruining my credit record...i am being bul****