Well for starters you should have waited for the person to receive funds in their account so it would of been an instant payment.
But if you gave all the information about the account to the guy, he can keep the account and cancel his echeque via his/her bank.
So, the best way to trade RS accounts would be that:
Seller: Receives x amount of money
Buyer: changes recoveries in x amount of days
Seller: receives e cheque and transfers to bankaccouny
Buyer: successfully sets recoveries.
If the buyer tries to charge back you can still get the account back because the recoveries havent set yet.