The packs contain a random assortment of items from a pool of common, uncommon, rare, and ultra rare items. You aren't guaranteed to get anything specific in every pack. Its like buying a booster pack of trading cards.
Sorry man. If you're looking specifically for a mount, your best bet is to buy it off the GTN. Mounts tend to be fairly rare (or ridiculously common depending on whether they are reskins or new designs).
As Acorn said, all of those are gambling packs. You aren't guaranteed any specific item, just specific qualities in each pack. You could theoretically buy 100 packs and never see your mount. Just buy them off the GTN for credits. You can sell anything from your pack to help offset the cost.
As Kelimbror said, it is a total gamble. I bought two packs to try to get Mira's Jacket rather than spend the then price of 1.5 mil, first page was 3-4 oranges, all 500 credit meh things but also the shimmering hilt lightsaber that I got 300K for. The second pack was fairly useless. No items of value, nothing important - or so I thought, the "useless" thing I got was a "regen health and resource" thing which was the "get eaten by something out of the ground" while I'm still trying to sell