So yeah ive bought the castle plugin for xbox 360 and ive done the quest up to where i have to buy the upgrades of Nilphas Omellian and he will not have them in his invo.

I've tried different times of the day.
Leaving the inn and waiting 24 hours and going back in.
Restarting the game.

None to which have given me the upgrades, so i was wondering if anyone here could shed some light on the situation.

Thank you inadvance.

I have no idea, but I'm just bumping this in case someone else does.

Did you get the deed from one of the battlehorn men at arms? Make sure you have talked to them, and tour the castle just for safe measures.

If that doesn't work and you haven't got ANY of the upgrades, you might want to disable the plug-in, save, and then re-install it. You'll have to save the castle again, but that takes less then 3 minutes.

Also take note that the Dwemer Forge will not be available until you buy one other upgrade, and travel back to Battlehorn. You should receive a message from one of the men at arms.

How would i go about disabling the plugin for the xbox 360?

I believe you would go to the memory menu, and either delete or move the Fighter's Stronghold plugin. Start the game up and save. Then re-download the plugin or put it back in and then start the game.