cannot evan trace my payment via the BARCODE ON THERE OWN STATEMENTS

I paid my MTN via the barcode on the statement ,becouse the mtn app firstly doe snot work when you want to do a payment does not matter on what device it is loadded , the idiosy of this company technical depoartment and call centre the app says we ran into a problem try again later, so none the less paying via the barcode on the statement , now MTN has handed the account over to colections eventhow it was paid with the barcode on the statement , and the traceing number from my discovery bank send as proof to them refferance after refferance , shame brain power for MTN lacks sjoe , i have no words anymore for it.... if they cannot find the payment thank goodness i only have a sim and if the still cannot find it , it saves me Five hundred and seventy rand a month for there incompitice not mine