Received court order after paying everything as agreed

Ive been paying my account as agreed to Mbd att since oct 2021. Since then I've been receiving calls, which i don't answer as i already made agreement to pay a certain amount every month. Last week I've received a letter with a court order that i should appear in court due to non payments made. I have all the proof of payments and the agreed contract to what i will be paying. I just want you this company to know that i will most def be seeing them and legal aid in court, with ALL the proof of payments and the agreed terms. I was fed up till i received this court order. ILL meet you in court. Wrong motherfkr