Breach of contract

On 30/04/18 i renewed my contract with you. I was supposed to get R120 airtime a month, paid the admin fees of R150. I cant phone out and nobody can phone me. Ive been to the Vodacom shop on the Bluff in Durban 3 times since then & they say they cant do anything about it. They reported the problem and said JHB never game them an answer. I'm very upset!!!! I told them to cancel the contract but they wouldn't, i tried giving the phone back but they not interested. I don't know what to do as i'm paying R230 a month for nothing. Absolutely disgusting service!