Business lines out of service for over 9 days!!

We have had business lines that have not worked since 6th January, we are losing business, and I keep getting told that the fault is "in hand" but how long does it take to repair. We have only had sms saying fault is being taken care of, but still no lines. I hope we will get a reduction on the account due to no service!!! Not impressed with the feedback as there is none! We have to make calls via cell which is expensive, wait on the line for a while to be told it is with the technician, but I think he has done a duck. Again - no feedback !! Please escalate this fault ref no 61CNZ060121