I have over 5 million coins but just about every time I try to purchase any the packs from the vending machine all I get is useless *! I just receive summoning zombies and the pot plants and building zombie mechanisms. I only have half of the uniforms and skins so my question is why isn't giving me anymore?
Different packs give different sets of customization so if you are buying the same pack its time to change it up and buy another set. When I got low and needed my last 100 items or so I was getting 1 to 2 a pack if I was lucky, some occasions I got zero for a few rounds of that.
I wonder what pack you're buying. I'm short somewhere just over 2,000 stickers, and I've been doing quite well with just buying the 15K pack. I'm getting two consumables per pack and often getting Super Rare and Special stickers.
I am really sorry for those issues with packs in PvZ: Garden Warfare 2. The items in those packs are totally random, but the chances to get something useful can be different in different pack types. But you can actually get some pretty awesome item even from the cheapest pack. So just keep trying, and you will get there eventually.