question on Supply trks/depots

[mac5732]

I bought ammo supply trks as part of my core units. When they came on the map, they showed that they did not contain any ammo of any type all 0s. I put out of supply tanks and armored cars next to them and in the same hex for 4 turns and neither of them were resupplied with ammo. I've used supply trks before in the scenerios etc and they always showed how much supply they carried and the units would resupply after several turns, but not this time...