I purchased a bunch, (10 or so), new in cosmoline, 25 round Littleton mags from them maybe 3 years ago, and they were HEAVILY packed in cosmoline. If thats the case, disassemble and clean these mags before you pick up the phone. ALL my mags ran great, but if yours don't, DSA has given me some excellent customer service over the years, and I'd bet they will exchange the mags for you, but, a refund after so much time has elasped may be expecting a bit much...
I'm assuming all your other mags run well?