Okay this might be cryptic but I will try not to be! If you bought something three weeks ago brand new and it was a duffer in the sense it didn't do what it was meant to - ie keep your feet dry then would you expect a refund or replacement product?
Makes no difference where you buy a product, your contract is with the shop not the rep.
I understand about not wanting to be too pushy, but they should also be worried about loosing a valued customer. How about putting a time limit on them? Maybe phone tomorrow, ask if they have heard anything, then say you think it is entirely reasonable to expect an answer by the end of the week?