ADSL service own but still paying for the service

My ADSL service has been intermittent since the beginning of December 2015. My ISP logged a fault and it was fixed just before Christmas. At the beginning of January 2016 the ADSL service started playing up again and I struggled with no ADSL and on some days no voice line service. I then personally logged a fault on 20 January 2016 and I have called numerous times to ask what is happening. I keep getting told a technician has been assigned to the fault and will be working on it remotely. I am at my wits end and ready to cancel this service with Telkom. It is **************** that I am been charged for a service and the service is not been provided.