I returned hundreds of dollars worth of product to walmart that I found dumpster diving
Why would you return items you didn't purchase to Walmart?
Because it's an easy way to get free money.
It's wrong to take advantage of Walmart by returning things they have thrown away. If they find out that you never purchased the things you are returning, you can get in serious trouble.
But I use that money I get from them to pay my bills and to buy things I like.
You are taking advantage of the situation. You shouldn't be selling garbage to anyone. If you need money, then you should get an honest job so that you can feel good about the money you earn and the things you buy!