Worst service provider insufficient service ect

Logged a call on 9th of December re our adsl line that was out... Eventually attended to 2 weeks later... THEN the line still drops and the call centre keeps telling us "the technician is working on it"..... so the call is still open and its the 27th of December. I have never dealt with such an insufficient unhelpfull service provider!!! Im not paying them another cent until this line is fixed, if my account is credited or not!