What is service delivery, Telkom asked?

I've logged a fault on the 21st of December 2015. ***. My land line is dead and adsl line is very slow. I've been phoning once a week to follow up (where i'm on hold for 30 minutes to an hour) to which they respond the job was forwarded to a technician and will mark it as urgent. On Monday i was told it has been assigned to a technician who was there on Sunday, but no one was there. Also have not received an sms stating it. What to do now. I am paying for a service which i'm not receiving. Do i stop paying until it's fixed, or just cancel the contract?<br>