VAC game gifts ability of charge back ?

of course there is, banks don't care about VAC or not.

If you charge back steam may retaliate on you, though. Like preventing future purchases.

and what about tradable VAC gifts that has been purchased before this update !! some people have L4D2 tradable in their inventories , so if we trade through steam window it should be normal trade and i can keep the gift in my inventory, right ?

For ALL gifts a refund is only possible if the person who recieved the gift agrees to that (if you were reffering to refunds).

Chargebacks can happen anytime for anything. Basically people give money to valve, sell the gift and then use their bank to get the money back (or used stolen credit cards in the first place).

Normally gifts should be safe after 30 days, so tradable gifts should be fine, but there might be rare cases, where processing took longer.

anyway thanks everyone