Read the rulebooks, point out the rules that this guy is breaking to him, and ask him nicely to create a new character more in line with the rules.

Come to think of it, while Vampire isn't exactly my strongest suit where WoD is concerned, I don't think that the current version of Celerity actually grants extra actions. Shouldn't that Discipline just increase Speed and Initiative, and impose penalties on attackers?

pre-vampire telekinetic abilities and pyrokinetic invulnerability.

If it's any consolation, this bit at least isn't valid by the WoD rules as written, since it would involve stacking two different character templates (Psychic and Vampire). Instead, by RAW, the PC should have lost the Merits for the psychic powers when he became a vampire, and (at the GM's discretion) the player might then have recovered some of the experience points spent on the old abilities as bonus XP towards similar Disciplines.