Proof of new address - no response

I contacted Virgin two weeks ago to inform that I am moving house to area with no Virgin supplied. I provided proof of new address but have had no response, even though they said they would be in contact in 3 working days. Currently, I am set to pay a bill over £300 for something which is not my fault. I am very disappointed by this poor service and complete lack of communication. Communication through the app is very poor and entirely through automated chat bots, who do not understand my issue. I do not recommend Virgin Broadband to anyone.