Upgrading without consent

My husband got a contract in September 2017 initially the contract was supposed to be R370 a month which was fine for the first I think 2 months then we started having problems the debit order stopped going off and we couldn't understand why we both work from 8-5 and my husband works on most weekends so we can't just go to a Vodacom store when we feel like it we always sorted out the account via the accounts department over the phone, then middle 2018 Vodacom decided to upgrade our contact so then we needed to pay R600 and something and we did not sign for this upgrade and we did not ask for it so eventually when we had time we went into a Vodacom store and the account was almost R2500 in arrears WHAT?? so we thought we got that sorted out we paid R1700 a few months ago because the account was in arrears and they have switched the phone off so we thought we sorted it out cause we actually went into a store this time. the last time this happend he phoned the accounts department and they said he has to go into a store because the contract that we have differs from the one they have and when he went into the store they told him that he has to phone the accounts department??? The debit order didnt go off because they wanted to debit R600 so now we were back in arrears with R1200 my husband was in hospital this last week and could not go into a Vodacom shop how is this possible that an R370 contract can go to an R600 contract without my husband actually signing any documentation or wanted to upgrade the contract, for almost 2 years we constantly have problems with Vodacom this is ridiculous we will not be renewing the contract and I will NEVER recommend anyone to go Vodacom.