What has cause the mix up and you to believe that FedEx are to blame? If it is their fault then you should be able to claim some compensation.
Oh the plus side, how long are you going to be away for? Jessops do a very good price match service and I believe a 14 day return option

Check that before you consider parting with you hard earned but it may just be a final option. Look after it and return it when you get back?
Obviously I am to honest to recommend doing such a thing but I am here to prive information