What is the ruling on insulting religion during the day in Ramadan, and does it invalidate the fast, and what are the consequences thereof?

Whoever curses the religion, while sane and willingly, has exited the fold of Islam. Such a person must immediately repent, utter the two testimonies of faith (Shahadatayn), and frequently seek Allah's forgiveness. If this occurs during the daytime in Ramadan, their fast becomes invalid, and they are obligated to make up for that day.