Xfinity Mobile won’t honor payment plan

I set up a payment plan on June 12th. I made my first payment, per the arrangement on June 25th. On July 1st, I received an email notifying me my service was suspended. I immediately contacted customer service via chat and then by phone. They claimed they couldn’t find any evidence of a repayment plan. They claimed they couldn't find the chat. I’d downloaded a transcript and took screenshots of the conversation on the 12th. They ignored me when I told them this and refused to give me contact information where I could send said proof. Moreover, they said I’d lapsed on an extension at the beginning of the year and they implied that the agent couldn’t have set up a payment plan….and inferred I was being dishonest despite the pile of evidence to the contrary. I have no evidence of this lapse. I reported this to the FCC the following day.