I am not a rep for the game, so I can't comment on getting your doughnuts back. However, to avoid this again, I suggest adjusting your options to confirm doughnut purchases before you buy so that doesn't happen again.
Click the house button like you're going to buy something. >> click the information (i) in the top right corner of the box that pops up. >> Under Options, click the "Confirm Donut Spend" button to ON. This will make it so when you go to buy something with donuts, it will ask if you're sure you want to buy it; that way you get a Dr. Nick instead of a Lumpy. Good luck with getting your donuts back though, let us know how it goes!
Same Problem... Was scrolling through the things i could buy with donuts and when i got to the end it just bought the purple funzo. i dont want something that dont even make money or gives extra experience. i would really like to have a refund but i bet they dont care about customer service so i guess ill just eat the 10 bucks of donuts used to buy the junk character. NOT HAPPY