Same thing happened to my wife.
48,000 miles, with an expiration date shown in February 2016. I checked several times last summer, every time it showed the 2/16 expiration date. Now I check, it shows zero miles. I'm pissed.
Will call them tomorrow and demand they reinstate her miles through the Feb date as previously shown. If they won't, I'll call BBB, CFPB, and will take them to small claims court. I might go there and make a scene, too. Perhaps go piss on the carpet in their corporate office. Find where the CEO lives and go defecate on his doorstep...
Do I smell a class action lawsuit? I think I do.
What complete slime bags.