A good iPhone 4 case with lanyard strap that can protect my phone during warped tour?

so I'm going to warped tour and I am going to be using my camera on my iPhone 4. I'm very scared it'll get ruined so I want to get a very good yet cheap (temporary) case for it. I want it to be either soft or hard shell. But if it's soft it can't be too soft cause then it stretches and my phone can come out. ALSO I want it to have a lanyard to put around my write that I can TRUST not a piece of crap. Andddd of course it must have a hole for the camera to be exposed . If you have purchased a case like this let me know! Thanks :)