Vodacom won't let me go

Mr A. Thompson called me regarding my network problem which i have with vodacom.. And has offered me to pull out of the contract with no costs.. He sent me an sms there after stating that they will cancell my contract and that he will get ppl to call me so i can port my number. But now to my surprise my number is blocked and now they say i must pay. What i need is proper network and I believe that mtn will give me that. i am tired of paying for something that i am not getting.