Gambling problem

So I just spent over 10 million SL into the latest gambling crates, and got 2 ships that can be sold on the marketplace for about 15 each. When I was finished wasting all of my SL, the coupons automatically got used and I received the vehicles.
Is it possible if I could prevent that in the future so I can sell the onto the marketplace?

Thanks

Not a bug, there is a considerably lower chance to get sellable coupons.