BAD CUSTOMER SERVICE

I recently opened a Mega U Account for my two twin boys, age 14. I received a message from ABSA on my cellphone for both my boys confirming the Account is now active with benefits to claim. I tried to log in and claim the benefits but it keeps on telling me the ID numbers is not on their system, "You have entered a wrong ID Number", I tried to call the call centre and was put through from the one department to then next explaining over and over again, the consultant did not understand what I was trying to say and rather told me to go into the branch to collect the cards. I tried to explain that I have the cards already and have been to the branch already. I am so frustrated. When opening the account I told them that I do not have an ABSA account and that I do not bank with ABSA, at the time this was no problem, so I would like to know what is the problem and if the benefits are applicable for them as well,. Can someone that knows just explain to me, as I am already sorry for opening the accounts, even thou my kids love their new cards and bank.