What should one do who vowed to fast one day, pray three nights, and perform three prayers in the mosque weekly after his success, but he does not adhere to what he vowed?

A conditional vow is disliked, but it must be fulfilled if the condition upon which it is based occurs, for the Prophet, peace and blessings be upon him, said: "Whoever vows to obey Allah, let him obey Him." It is obligatory to promptly make up for a vow that was time-bound and has been missed. The majority of scholars hold that an expiation for breaking an oath (kaffarat yamin (definition)) is not required along with making up the vow, but it is more cautious to offer expiation along with making up the vow to avoid scholarly disagreement.