Last Thursday I emailed my contact at Sabre Defense asking when I could expect to get a reimbursement check for the shipping charges I paid to send my upper back to them:

Aloysius,
I'm pleased with the quality of the repair/replacement Sabre did on my M5 (it feeds like a champ now) and I'm not trying to be too much of a tightwad, but when can I expect to be reimbursed for what I paid to ship my upper back to have Sabre's mistake fixed? If whoever packed my upper to come back had thrown a magazine or some other bit of schwag in the box along with the upper that would have been great and I wouldn't have said anything more about the shipping, but I'm out $14.46 (the FedEx receipt is sitting in front of me) which isn't a lot, but it's money that I had to spend to fix someone else's mistake

John
This morning he responded and asked if two 30-round mags would make up for my trouble since it's easier for him (less paperwork) to send gear/mags vs. getting a check issued. I though, ohhh, 2 seconds and wrote back that I'd be more than happy with that deal. Heck, I'd rather have a pair of mags (Sabre's OEM's are pretty good quality and work well) than ~$14 so when the time comes that I "need" another AR, Sabre's back on my short list b/c of the good service I've gotten from them.