PROBLEM WITH LOOK ALIKE LINES

It has been a while that we had our lines replaced with "look alike lines" by Telkom. We have had nothing but problems since day one. One is unable to hear the person on the other side, the line is never clear. The latest problem we are experiencing is that we are unable to make calls. A messages states "YOUR FUNDS ARE INSUFFICIENT". Please tell me I have wrong. We have an account with TELKOM, the only thing that has changed is the instrument we are using. This is a very huge business concern and it is ridiculous that we as a paying customer suffer because ******* ***** the TELKOM CABLES. We want this problem solved, once and for all. On is unable to get hold of anyone at TELKOM who can assist.

Thank you