Account upgraded without my consent

I've been battling with Vodacom for this whole year. I have four cellphone contracts with them which most of them are due to expire this year(2021) but they somehow managed to upgrade my contracts without my consent. I have successfully managed to cancel one contract which they upgraded. I called them on August trying to cancel a contract which was supposed to expire end of September, but I was told I can't cancel it because it expires in March 2022, when I asked how's that possible, I was told my account was in arrears and every time when an account is in arrears the contract term is extended, I couldn't understand how because I always settle my arrears. This account falls into arrears because they don't debit on some months. So today I went to Vodacom to get clarity on this matter I was told two of my accounts were upgraded in April, but I was not told this when I called in July. I have fallen into tough times I can't afford to continue with this contracts that were upgraded without my consent. Why does cancelling a contract have to be such a hassle with Vodacom. The consultant on the phone was very rude, it seems like she didn't want to to all to me. I'm really stressed. Please help.