Cell C Fibre Horrible Service

I was migrated to Cell C cfibre from Greeencom in late 2017 and my fibre line stopped working. I have been complaining since December 2017 and they never sent any technician to fix the line and as such I refused to pay for services not rendered. By the time the sent a technician late 2018, they had already blocked the line. To my disgust they still want me to pay R7000+ for services I never received before they could reopen my line. what ******* is that.

everything was working well with Greencom and they sorted technical issues out very quickly. we communicate with technicians directly but at cell you have to call a customer agent who then forwards your query to some ghost technician and respond with unhelpful email.

Does anyone have advice how I can sort this out? please I run a small business at home and I want my fibre line. mobile data packages are expensive.