Vodacom unfair cancellation policies

My Vodacom account is in arrears. I know this is my fault and I am liable for that money. However, my ex has not been paying maintenance and the account has fallen behind. I have tried to cancel contracts that have expired, but it seems Vodacom will not allow this until the arrears has been paid in full. If I could afford the contracts, I would not cancel them. If I had the money to pay the arrears, I would do so immediately. However, it seems to be Vodacom's policy to keep charging for expired accounts, ensure that my arrears keeps building up, and cripple me financially. Thank you, Vodacom, for making it clear that you don't care about my problems and ensuring that I can't make responsible financial decisions. I was trying to prioritise feeding and educating my children, but I guess that won't be possible since Vodacom feels it's more important to keep billing me for expired contracts.