A new contract I did not ask for

I have been a client of Vodacom for the past 18 years with good service. I have at the moment the following contracts: Sel... ********** 031 Tab.... ********** 196 Mod... ********** 500 On 1 April I was due for a new contact on my modum. I had a 2G contract but a special was on for 5G at the same price. On 1 April I was advised the the special was no more. MTN had a better deal. The shop advised me that I have to phone Vodacom to cancel my contract with them. Vodacom, during my sel conversation with them told me as I was a good client of them for more than 18 years that they will update me to 5G at the same price as befor. Narurely I was glad BUT!! Instead of upgrading my modum contract to 5G they upgraded my tab from 500MB to 5G. I previously paid for the tab and 500MB +_R128-00. now it was +_R190-00 I in the meantime upgraded my modum to 5G and requested that my tab contract should be reinstated on the same conditions as before. The local shop assisted me by lodging a request to reinstate my contract to the original conditions....no luck. They lodge the queries and then Vodacom phone me to say that the querie was solved. All they do is to "migrate" the contract.at the price as before and the 500MB BUT the contract runs for a further 2 years!! I was due for a new contract and a new tab on 1 June 2018 but is now stuck with a contract I never asked for. All I ask is that the original contract as before this confusion be reinstated. It is frustrating negotiating a contract over the phone. One do not see the conditions of the contract nor do you sign anything. I was refered to you with high praise and would appeal to you four assistance. Regards, Philip