So after some confusion, and immediate suspicion, I have discovered that the T-34-3 Black uses Gold to resupply HEAT shells even with Silver being selected as the resupply method.
Noticed missing Gold, got it back and noticed the ticket said I used it to resupply ammo on said tank, checked ammo cost and verified I have Silver selected, played a match to test suspicion and sure enough ot ate my Gold.
Not sure if this is just a bug only I'm dealing with, or if any other vehicles are also affected.