All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
Allah has ordered us to fulfill the contracts and abide by it’s conditions in general as He Says (what means): {O you who have believed, fulfill [all] contracts.} [Quran 5:1]
Also, the Prophet said: “Muslims should honor (abide by) their conditions.” [Abu Daawood; As-Suyooti classified it as authentic]
Hence, if one of the parties of the contract fails to abide by what was agreed upon, then if this happened from him unintentionally and he did not repeat this, then it is recommended to pardon him, but it is not obligatory to do so.
However, those who neither abide by the contracts nor fulfill the conditions, and do this habitually, then such people must be disciplined even if this requires taking the case to a third party that would force them to do what they are obliged to do, and punish them for their negligence about the rights of the people so that they would be deterred and refrain from harming others.
Forgiving such people would encourage them to continue violating the conditions and would make others act like them.
Imam An-Nawawi said:
“With regard to the person who is known to do this, i.e. corruption, then it is not recommended to conceal his flaws, unless exposing him leads to a disadvantage. This is because concealing such a person would encourage him to harm, cause corruption and violate the prohibitions, and would encourage other people to do the same thing like him.” [End of quote]
Finally, it should be noted that it is the owner of the right, or someone whom he authorizes to do so, who is entitled to give up the right but not anybody else.
Allah knows best.