I tried to cancel Cox Communications for my sister who had a stroke and was in a coma b...

I tried to cancel Cox Communications for my sister who had a stroke and was in a coma before she eventually died. They said they would cancel, but then they sent a bill that they claimed was past due and continued to take money our of her bank account. We have to keep her bank account open while her estate goes through probate. They argued that since she was the only one listed on the Cox account, they could not open it themselves to take action and that I needed to present myself to the nearest Cox office with a copy of her death certificate to get anything done about it. We live in Pennsylvania - where is their nearest office? They were completely unhelpful and insensitive, so we have contacted our bank and our lawyer to get them to stop helping themselves to the estate of my dead sister. She was a good customer for many years, but had tried to cancel herself just before her accident because she could no longer afford the rate increases.