Listed on ITC in Error

I have been trying since September 2014 to have an error on Multichoices side to be rectified where they listed me as a default payer for 30 days on an account that is paid via monthly debit order and where monies were in fact received from them. On 23 January 2015 Phehello from Billings & Colletions said it will be sorted out. WHen I phoned today, the next agent says there is no info on system. I have all email sent and all case numbers, yet nothing gets done. what does one have to do to get some service from a bunch of pathetic call centre agents? I want senior management to sort this out by close of business today