Lack of service

Our 4 meg ADSL line was installed <br> 1. It has never worked at that speed <br> 2. It constantly fails and drops the link . <br> 3. We have reported this repeatedly. The latest incident 3 weeks ago. It is still failing. We keep getting told the fault has been resolved. Yet we cannot even work what's app off the ADSL. A technician has yet to come out. No one has called us. <br> 4. We were sold a service they cannot deliver and are unable to resolve. <br>