Systems nor close to good enough

This review is not on Edgars itself but on their systems. It ha now happened three times where I have paid two or three times the amount due (by the first f the month) but still receive sms's more than a week later to state that I have not paid. When calling the call centre, whose number is included in the SMS, they always see the payment and say that the SMS is an automated message. How can a large company such as Edgards / RCS have such bad systems? It should also be noted that I pay every time at an Edgards branch, so it is not a case of the payment being stuck between different banks.