Lacking customer service

I've been using Vox for about 4 years now, I have moved houses and I sent a mail a month prior to ask them to please de-active my old address and to active my new address. 2 weeks later, they have not activated my account and I am being told that my account is not active due to non-payment. I have been calling and I have emailed through the POP for them to see that payment was made but all they keep saying to me is that my account is not active. I have been using the same account and payment method for 4 years and somehow this last payment is not received - how?? They lack customer service! You can spend the whole morning/afternoon calling, being transferred from one line to another, that time you keep topping up on airtime. I am currently looking for a new ISP!