Is a person who twice paid a bribe to obtain an exemption from national service sinful, even though he was deceived and did not receive the exemption, and his status remains uncorrected?

Bribery is money paid to invalidate a right or validate a falsehood. It is permissible to pay money to obtain a right or ward off injustice when in a state of necessity. Therefore, if you are entitled to exemption from national service, but cannot obtain your right except by paying a bribe, there is no sin upon you, as long as you are compelled and averse to it. However, if you are not entitled to exemption, then what you paid is considered a forbidden bribe, and you incur sin for it. The failure of the person you paid to fulfill their promise does not absolve you of the sin. In all cases, sincere repentance erases the sin.