Selling my car and can't find the service history for the life of me

It's a '14 plate, I had it serviced regularly, I can find one invoice showing the service but the book is nowhere to be found. Have a sneaky suspicion my 4 year old nephew binned it when he was rifling through the glove box recently.
Am I totally screwed without this? I had it serviced at an independant garage (who have been hopeless, tried to call them, say they have no records.)
My new car is coming Tuesday and I'm worried I won't be able to sell this one and I'll be stuck!