BAD SERVICE

Recently while checking my bank statement, I realised that my March account was more than double the normal premium. When I checked my April invoice I got an even bigger shock. I then stopped my debit order. Friday 8 May I got a message informing me that my line will be suspended if I don't pay, it was suspended straight after the message. I called the call centre and explained the problem, got a reference number. I also send an email and got a reference number. I requested to speak to a manager and they said a Manager will contact me, that never happened. Tuesday 12 May I called again and was transferred from the Credit control Department to client services, again I explained my problem. The Gentleman suggested that I speak to Credit Control and that they should be able to assist me. I then spoke to Petuna who said she will help, but she just transferred the call back to client services without any warning. I called back several times and tried to speak to her, but the call was either dropped or transferred without her speaking to me. I tried to speak to a manager, but no luck. I have been a good client for 18 years and now I get this treatment. I don't know what to do anymore.