Why do you have a call centre

I recently closed my cheque account and opened a new cheque account with fnb. In other words, the bank I am with,stays the same, only my account number changes. So, I asked fnb to move all my debit orders over to the new account,all done by phone. My standard bank order was rejected. I phoned the home loan call centre to no avail...Now I have to write a letter and sign it to modify an existing debit order. Why can all the other debit orders be moved and changed so easily but standard bank is the only one out all the debit orders I have to Not want to be paid. Why even have a call centre if you never get serviced and have to go to the branch anyways... This is not the first time that the call centre meant absolutely nothing to me... I want my bills to be paid and up to date, I don't slack on payments ever! Standard Bank... Pull up your socks!!!