Friends can let us down, even Jesus experienced this... Judas was his friend, the Lord chose him as one of his twelve disciples... and Judas let him down.
But according to God's word what someone sows they eventually will reap. We are not to judge, the Lord will take care of that...
Luke 6:37
"Do not judge, and you will not be judged. Do not condemn, and you will not be condemned. Forgive, and you will be forgiven.
Luke 11:4
Forgive us our sins, for we also forgive everyone who sins against us. And lead us not into temptation.
Heavenly Father, I pray for this person that You would take care of the problem as this person needs these finances. I pray Your mighty blessing upon him/her and bless him/her above the amount that is borrowed and not given back. I pray You hear the cry of his/her heart and come to his/her rescue. I pray for abundant blessings. In Jesus Name. Amen