Customers cannot hear us talking, but we can hear them

We are receiving horrible service from Comcast. We've had this issue pop up intermittently since we installed VOIP phone services with Comcast. Now only is our internet signal far below the level we are paying for, but more importantly our phone system is not dependable. This makes our business look bad. Comcast sent out technicians to fix the issue they found with the wiring outside from the node. This fixed the issue for one day, and the following day after the technicians left we receive a message stating that some of the wiring for our service was loose. I do not have endless amounts of time to sit on the phone with CSRs. Mostly, I will not let Comcast ruin our business image by providing a shoddy product. 

These issues need to be fixed ASAP without our personel having to enact the fixes. Perhaps legal action will be necessary.