I can't find a Rainforest biome in Minecraft? (1.7.5)?

Hello I'm playing Minecraft, and apparently i have no luck in finding rainforests. I'm playing survival and was looking for Cocoa beans. I didn't think they would be that difficult to find but I was wrong. I had been walking around in Minecraft for 2 straight hours without crossing a single rainforest. I have been through deserts, Snow biomes, almost everything EXCEPT the rainforest! (it may sound silly but I was looking for Cocoa beans so i could craft Cookies.) lol
Well i'm really tired and I feel kind of down. My brother spawned in a rainforest in his server and is having no hard time finding a bunch of coca beans…

It's called a "jungle", not rainforest. They're usually quite common, so I guess it's just bad luck.

If you give me the seed of the map, I could fly around and find one for you.

Check the grass block if it changes color (If it's black that means your close to the rainforest)