extremely poor customer service

i had a contract with vodacom on ***, i cancelled the contract in feb as it was due for cancellation on the 7th of feb 2016. on the 1march 2016 i bought bis for R60 and as the sim card was now on prepaid, it allowed me to do so, R60 was deducted from my account and vodacom sent me an sms to confirm that the bis will expire on the 31march 2016, on the 2nd march 2016 when i tried ti log on to the internet, a message popped up to say the price plan i am on is not supported, i need to connect to a wifi or buy bundles...i have been trying to contact vodacom eversince with no luck until today, one agent is telling me my number is on contract, another is telling me it is on prepaid...the next thing vodacom will tell me i owe them and call everyday for their money, but now no one is willing to assist me.i have been with vodacom for 16years and this is by far the worst service...what am suppose to do with your simcard? you have dissapointed me as a service provider and your call centre agents have no way of communicating with a frustrated client, i spoke to nomfundo as well as dikeledi, both were not symphathetic to my frustrations.