Is it permissible to give charity instead of fasting for two and a half years for someone who finds fasting difficult and has many sins?

The question includes two issues:

First: The abundance of sins and their cure through sincere repentance with its known conditions (desisting, regretting, resolving not to return, and restoring injustices). Allah accepts the repentance of those who repent and transforms their bad deeds into good ones, and one must not despair of His mercy.

Second: Obligatory fasting, where one must fast what absolves their responsibility, and it does not transfer to feeding unless according to specific legal stipulations. Feeding is for each day a poor person and has no relation to sins. If breaking the fast was by intentional intercourse during Ramadan, then the major expiation is obligatory along with making up the fast. Delaying the making up of Ramadan fasts until the next Ramadan begins necessitates, along with making up the fast, a minor expiation, which is feeding one mudd to a poor person for each day.