cutting off my service

My bill is paid monthly via my bank automatically. My bill was paid last month AS ALWAYS automatically and I am getting emails threatening my service saying I didn't pay it. I have called many times, given you the proof from my bank including their case number that they used to verify the bill was paid.  The amount has been deducted from my account. I cannot get anyone to look into this-this is on YOUR end, not mine. No one else I pay has not rec'd their payment- just you. The last time I called I couldn't understand a word the rep was saying, asked for a supervisor and same thing. Not only do I live only on social security, I am not paying TWICE for something that was already deducted from my account. This is totally on your end and I need it resolved. I can't respond to the emails and calling is no help.