And reading their ToS, it looks like we're all $#% out of luck too... Although the fact they had a DB error it's kinda their fault...unless they are blaming bitcoin then they are not responsible for that either according to their ToS.
According to their Terms of Service:
If an order cannot be filled by Coinabul we will either: provide a substitute product of your choice of equivalent value, or provide a refund, minus any market loss incurred and at our discretion.
That's pretty bad. If they are going to lose money on a sale, they just refund you, but keep the amount of money they would have lost. Basically, it means they can steal your money.