If he has a ground to cancel that, then, he can cancel the contract. The realtor can cancel the contract.
Can he get any form of refund?
Since, he is already paid since the past 30 months, you might ask, "can he get any form of refund for cancelling the contract?"
Granting that he's cancellation is meritorious, initially, the law allows him a grace period to pay that. Unless he has the ground to cancel that, he cannot cancel that just for the sake of cancelling it.
Basta nagbago lang ang isip niya, ayaw na niyang bilhin, he cannot get a refund of any of the installments he already paid. In that case he's the one who is violating. It's already bounding. When he signed the contract, he is already bound to the contract.
What if he has a reason to cancel the contract? Can he cancel the contract?
Meaning the condominium was late in the development or meron silang substantial deviation which means they violated what they promised to the buyer, he can cancel the contract. And since he has already paid 30 months, if there's reasonable ground to cancel, then he can get full refund (even with interest).