Thank you to both for the replies -have filled it out on-line thinking it would be an auto-generated and instant response as the BA booking engine would be able to instantly verify against my Exec #, booking reference, dates etc etc.

Not to be - I certainly did get an auto-generated reply but only to tell me it can take up to 28 days to get the requested receipt. How bizarre....given the amount of specific and detailed info requested, why on earth is this not just automatically verified within the BA booking system and a duplicate e-mail confirmation sent to me?