I have the same notice too, saying my remaining balance is the full price even though I'm on flex and I've already paid over half the price. Since Cap will ship soon after my last payment is made in two days, which was confirmed via e-mail, I'm just going to ignore the notice.
They must be getting more in, I had a problem with one of the seams on the pants of mine a few weeks ago and they said I had to wait for they next shipment for parts. Got an RMA to return it for an full exchange a few days ago (I don't know why they are going that route rather than just sending new pants but whatever).
happy 4th! in honor here is my small mod on cap. never liked how they pinned his ears back so i popped them out. i slit behind his ears and put sculpey in it to hold them out. this was the head i did for stealth cap. painted his chin strap as well.