Worst ISP ever

The cannot do anything Right, I have been battling with their online support to resolve an MTN VoWifi Issue, even explained how to fix it, been chatting for 2 weeks, and they just keep on escalating it, now they say I can cancel but must wait for 30 days to release the line to the new ISP while they cannot resolve my issue. So I msut just pay for nothing.... They cannot even get a cancellation right