*********** customer service

I have a contract with Cell C and ever since I upgraded my contract in 2018 I've been having endless problems that fail to be resolved by them. One of the main issues was during covid when I wasn't getting an income and they didn't have any payment plans for their customers, this year they sent me a bill stating that I need to pay them R13 000. I've been trying to contact them since last year but I haven't got a response from them, my emails having been bouncing back and they've been cutting my calls when I try to get hold of them.