Guess I'll just eat the return shipping cost then. I like the feel of the keyboard, so maybe I will pick up another Model M down the line. Fortunately my Ducky works just fine. 
Before you do that there's a few quick fixes you can try.
First of all, was it the one
from this post ? I just got mine in and wrote up a
quick review.Do the keys sound different when you press them? this can help diagnose the issue.
So usually if just a few keys aren't working, it's a fixable problem. Here are a few things to try.
#1 and this is usually the case: the keycap is mis-seated. Just remove the keycap and replace it. If that doesn't work first try, try a different keycap just for testing. sometimes (rarely) the keycaps aren't moulded correctly.
#1.5 : spring not working right: in this case, you can swap the spring with a chopstick.
Harder fixes
#2: dust under the sheet. This is uncommon and usually only happens after the KB is opened for bolt-modding or other maintenence.
#3: hammer mis-seated. This is also uncommon, especially for a new KB. The fix is usually to open it up, cut all the rivets off, drill holes where they were, install bolts, re-seat the hammer(s), reassemble it, screw nuts onto the bolts and then test it.