Problem with PS2 game

I have a problem with Star Ocean 3: Till the End of Time.

Whenever I get about 10 minutes into it, it goes into the battle simulator where it transmits into the battle system. Whenever it does this it just hangs and doesn't actually load into the next scene.

I've cleaned the disc and I've tried a few times to get past the same point. But it just hangs.

I'm not sure if there's anyway to clean the PS2 lens either, but all my other games seem to work fine. And I bought the game online, and tried contacting them, but no answer in regards to a refund or exchange. =\

Edit: Nevermind, I ended up contacting the store again, and they said it was a bad shipment for Star Ocean 3, and that they'll test a new copy and send it to me.