Simple request to change billing address can not be completed

I have had constant problems with MWEB - I am tired of constantly calling and emailing as nothing is done as is suppose to be. I had a simple request of changing my address on the billing statement from my home address to postal. It is so simple yet no one at MWEB can complete this task.

I changed it on the application I submitted in June, I called again and was asked to complete a change in details form which I did and sent through again on the 4th September - why is it so difficult? I want this completed before my next statement goes off.

MWEB account number is ********** 9