Bad customer service

My name is Poppy and I am not a client of Discovery bank, I am applying for exemption for my son at he's school I was requested to get discovery bank to assist me in confirming whether I have a bank account with them or not, I called in on Sunday I was told to send through the page for a stamp and my ID via email as they do not have a branch in Pretoria central, I called through within 48 hours and I was told they received the documents however I have to resend the hole document as they need to see the full information which is already stated on the page I sent through to them via email as feel the document is a personal one and they already have my full details as I attached my ID copy, then I was told once I email I will wait another 48 hours being getting back the document. I find it unprofessional as they already have all my details and information why do they need to go through the hole document as I only need the bank stamp and signature.