Dennis, I would have sat tight for another two weeks before I did anything. I have had chips take a month to get to me before after getting lost in the USPS system. Bad things happen; family members pass away, people get sick, and so on. If I remember right; weren't you the one who had to leave the convention early last summer due to an illness or death in the family? If that was you then you should know all about how life gets in the way sometimes.
I think it is apparent that you pulled the trigger on the neg feedback a too soon. When I leave negative feedback for someone it means I have given up all hope of a positive outcome and exhausted all avenues. At this point, I would apologize to the seller and hope the seller sends you your chips but if it requires much intervention from the seller, I seriously seriously doubt you will ever see them.
Regards,
Bill