Having_Trouble

I have tried reflega and curb. I don't usually use a ton of magic when fighting. Most of the videos I watched only use reflega and curb though. I don't have any problem actually defeating him, but the battle doesn't end!

Please help, I am completely lost, frustrated and want to give up on KH2 Final mix!!! I arrived to the final world to confront Roxas and cannot win! I have killed him over a dozen times (completely draining his life), but he remains alive and very much interested in destroying me! Imagine that you are fighting this boss (which was challenging when I first attempted) and being so excited when you strike the final blow, completely draining his health, and NOTHING happens. He continues to fight me and fight me until I am out of potions and MP. I have literally fought him after his life had been completely drained, almost to the point that I would have hypothetically drained a whole 1+ health bars. I am only playing through the game on Normal (so it shouldn't be anything too ridiculous...right?) These are the things I have thought and/or tried: -I thought, maybe I needed to level up, so I did that and I am currently level 51 which I know is much higher than needed. -I am officially stuck as I have completed everything (and I mean EVERYTHING) in the other worlds. Which I know is not necessary because people say they leave some things/battles for when the acquire final form. -I have fought Roxas 'normally' and beat him, finishing him with a combo, finishing him with the reaction command. I know this seems ridiculous, since I have watched numerous tutorials on youtube that have shown people defeating Roxas with no need for special hits (but I am desperate). -I thought maybe the disc was corrupted so I tried another disc, but the same thing happened. -I don't know how this would make sense, but could it be the PS3? -Someone's theory who I talked to was that the save file was corrupted, but others I speak to think that makes no sense since the only thing that doesn't seem to work is the battle ending (even though I kill him)! I have been able to complete everything else in the other worlds fine. I have scoured the internet looking for anyone who has experienced this and I cannot find a single person or incident of this happening. I asked a local gaming store for help and they had not heard of this happening before. Many of the KH fans said that I needed to finish Roxas with a combo or special reaction move!! Which is frustrating as I have watched videos where they kill him without using a combo/reaction command. I would really appreciate any help as I am getting incredibly frustrated and my desire to play is slowly and unfortunately diminishing!!!