I think you're being too nice, it's their fault you've been without the car for a month, it's their fault they sold your wheel, (not the first time either) if it were me I'd suggest they send a brand new wheel to the address of your choice so that you don't have to go all the way up there again and when you've got the new wheel ask them to arrange collection of the old one or keep it as a spare. You have the problem, they have effectively given up and taken the easy way out, this is still going to cost you time and inconvenience. They should be "owning" this problem totally, as it is they've tried, given up and left the customer to his own devices which quite frankly isn't good enough.
Maybe ask Ricey to write them a "nice" letter. You could do worse Hope you get it sorted soon mate