I got my Oscars two days ago. They are about an inch in length. I bought medium pellets to feed them but the kept spitting them out. I thought they did this because the pellets are to big. I went out and got some mini pellets but they spit these out too. All water conditions are fine and they will eat blood worms.

you could try a cichlid flake(here we have a product called cichlid crisps that is available at petsmart) they might go for that.

There are no petsmarts in my area and the fish stores in the area don't have cichlid flakes,

OK I solved the problem

I smashed the mini pellets with a hammer and now there even smaller and the Oscars are eating them.