Continuous billing after disconnect.

 On July 1 2020 I called to disconnect service from my rental home in Michigan. The agent said the equipment must be returned and sent me a label. The equipment was boxed and the label attached, it was dropped at UPS July 10 and received by Comcast in July.  I moved to California July 4. Comcast reports they have no record of the call to terminate service, and continued billing. A new tenant applied for and received service at that address in August, nevertheless Comcast continued billing me though August, September, and now in October. I called customer service 4 times to stop the billing and to obtain a credit. During my last call I was informed service was finally terminated September 26 but there were no credits. Formeruser.