Even I, a mere human, know that when I forgive my son a debt, it no longer exists. I do not forgive his debt, then demand repayment...
Er, if I may add a few cents here. God will forgive us exactly the same way we forgive others to which we agree every time we say the Lord's Prayer.
And forgive us our debts, as we forgive our debtors. - Matt 6:12
Forgiveness is precondition to having our petitions granted. After the Lord's Prayer, He says:
For if ye forgive men their trespasses, your heavenly Father will also forgive you: But if ye forgive not men their trespasses, neither will your Father forgive your trespasses. - Matt 6:13-14
And again here:
Therefore I say unto you, What things soever ye desire, when ye pray, believe that ye receive [them], and ye shall have [them]. And when ye stand praying, forgive, if ye have ought against any: that your Father also which is in heaven may forgive you your trespasses. But if ye do not forgive, neither will your Father which is in heaven forgive your trespasses. – Mark 11:24-26
God's justice is absolutely perfect. In this life, we build the scales whereby we ourselves will be judged, measure by measure, weight by weight:
Judge not, that ye be not judged. For with what judgment ye judge, ye shall be judged: and with what measure ye mete, it shall be measured to you again. - Matthew 7:1-2
That is why I personally do not demand restitution. I forgive absolutely and also forget.
Judge not, and ye shall not be judged: condemn not, and ye shall not be condemned: forgive, and ye shall be forgiven: - Luke 6:37 Blessed [are] the merciful: for they shall obtain mercy. - Matthew 5:7
I do not expect to be subjected to a purgatory because I do not demand restitution from others. To God be the glory!