I tried and tried but I couldn't get 20% off and free shipping. Oh well, it was still a good deal, thanks!
Keep calling and get different people until they do it. I called twice and the second person did it. I basically told them I placed an order 2 wks ago and now have this code could they please apply it to that order.
Funny thing is, they didn't even ask me for the code they just did it and told me what the adjusted total was.