Communication

I recently bought a new property and accepted a home loan from FNB. At the time of going through the process I asked if it would be possible to look at a fixed interest rate at all, and they advised me that I can phone and request a quote once my first debit order had gone off, which I was happy with. I then phoned after the first debit order went off on the 28th of Feb and they said, no I have to wait 6 months? Why is that? Please advise? I would like to get a quote.