Ignoring my requests to sort out an overcharge.

Last month I was overcharged by more than double the amount of my usual statement, I sent in a mail and also contacted live chat. They just keep saying they are investigating and after that I sent another mail, It's been 2 weeks and no answer. I sent 7 more mails and they are not responded to. When I used a different email and made up a **** complaint they responded almost immediately which proves that vox is ignoring me about my overcharge.