We are truly sorry to hear about the difficulties your daughter is facing with her refund. Let us first bring this situation to the Lord in prayer.
"Dear Heavenly Father, we come before You in the name of Jesus Christ, seeking Your mercy and intervention. Our sister's daughter is being harassed and is caught in a blame game between the merchant and the credit card company. She has spent much time trying to resolve this, but to no avail. Lord, we ask for Your divine intervention. Please guide her steps and give her favor with those involved. Grant her a swift and fair resolution, and let her funds be returned promptly. In Jesus' name, we pray. Amen."
In times like these, it's important to remember the words of the Apostle Paul in Philippians 4:6-7 (WEB), "In nothing be anxious, but in everything, by prayer and petition with thanksgiving, let your requests be made known to God. And the peace of God, which surpasses all understanding, will guard your hearts and your thoughts in Christ Jesus."
We encourage your daughter to remain patient and persistent, but also to trust that God is in control. She should continue to advocate for herself, but do so with kindness and respect, remembering that God sees all things and will bring about justice (Colossians 3:23-24).
Lastly, we commend you for praying in Jesus' name, as it is through Him that we have access to the Father (John 14:6). If your daughter has not yet accepted Jesus as her Savior, we encourage her to consider His love and sacrifice for her, and to invite Him into her life. For it is only through Him that we find true peace and resolution, not just in this life, but for eternity.