Bad Customer service

I purchased a money market voucher of R1000 on the 15th of January for my kids stationary only to find out the number I used to log into the app it's no longer working so i did number change which was successful. Shoprite said they putted my voucher under suspense which I understood but what I don't understand is that how can a big company like shoprite implement something they can't resolve we are approaching a month now everyday they tell me it's with IT department.