TELKOM SENDS INVOICE TJAT SAYS YOU PAID BUT WANT BLOCK YOUR LINE CAUSE YIU DID NOT PAY?!

Received my invoice yesterday, dated 01 November, on the invoice Telkom says "payment received, Thank you" and the amount paid. It states on the sam invoice that the next payment deu is 30 November 21. TELKOM NOW SENDS SMS THAT MY ACCOUNT IS IN ARREARS AND MY LINE WILL BE BLOCKED, I WILL BE BLACKLIST AND ATTORNEYS WILL BE ALLOCATED TO COLLECT THE MONEY'S!!!

HOW DO I PAY AGAIN FOR SOMETHING THEY SAID THEY RECEIVED AND SEND ME THE PAPER WORK TO SHOW I PAYED???