debit order went through but still shows as owing

i was behind with my account for 3 months. on the 19th of April i paid R1648 to settle my arrears including my installment or April. my contract always deducted on the 25th of every month. i called in after the payment made and i was advised my next debit order will be on the 25th of May 2020. May came and a debit order went through on the 25th which put my account up to date. to my surprise, on the 28th of May, i received an sms to say they did not received my payment. i called me numerous times, i sent my bank statements and the sms to say it has been debited and i am advised i was suppose to pay cash.. i am very angry and ****ed of.. i want to know what is happening with this account as it was debited on the 25th, but it still shows im in arrears. ***. i want an explanation now