Repentance is the first step towards salvation. It is not a guarantee against punishment.
That's right. "Believe upon the Lord Jesus Christ" for the full payment of one's sins "and thou shalt be saved" (Acts 16:31)
God sent His only begotten Son to be the Gateway to heaven. Anyone who believes that He died on the cross for them, for all their sins no matter what they may be, is Saved positionally right then and "shalt be" that is absolutely shall go into heaven and be safe.
There is no sin that is not covered, there is no other plea. No matter how bad, no matter the volume of them - believing upon the Lord Jesus Christ's payment of them is completely sufficient.