Do you see a ticket number on the BA App after refreshing it?
I don't think you need to worry, if you call up again all you are going to get is a repeat of what the agent already told you / emailed you. However clearly at OLCI, if that doesn't work, you need to be straight back to the BAEC Contact Centre about it. MMB / relevant flight / "More flight information" should give you the Selling Class.