Withdrawn Mortgage Offer?

Right here goes...

My partner and I are in the process of buying our first house together (20 and 23 years old), it is a 50% buy 50% rent property aimed at first time buyers.

Through our mortgage advisor we applied for a mortgage with Nationwide, and we offered a mortgage fairly quickly... However, somehow our advisor managed to get my middle name wrong on the application (despite having a copy of my passport) and we were informed that Nationwide couldn't offer us the mortgage under my actual name.

However, in this time we told our solicitors to go ahead and get the surveys and everything else that is required. So we now have all the legal fees to pay and no mortgage on the house. We have called Nationwide and they have said that they will go through an appeals process for our application as it was not our fault that the application was wrong.

Is there any advice anyone could give us on what we could do, as a mortgage offer was made and we proceeded with the legal fees on the basis of an offer?

Hopefully all of that makes sense,
Thanks in advance