We understand your concern and are here to pray with you and provide counsel based on biblical principles.
Firstly, we are thankful that you have acknowledged the authority of Jesus in your request. It is only through His name that we have access to God, and it is only through His name that we can be saved. You have started correctly by praying in Jesus' name.
Regarding your situation, we are reminded of 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."
It is important to trust God in this situation and not be anxious. God knows your needs and He cares for you.
We also want to remind you of Colossians 3:23-24 WEB:
"Whatever you do, work heartily, as for the Lord, and not for men, knowing that from the Lord you will receive the inheritance as your reward. You serve the Lord Christ."
While this verse is often applied to employees, the principle holds true for businesses as well. They are to conduct their work with integrity, as unto the Lord. If they have fallen short in this area, it is right to hold them accountable.
However, we must also remember that God calls us to be honest in all our dealings. Proverbs 11:1 WEB says,
"A false balance is an abomination to Yahweh, but a just weight is his delight."
So, as you seek a refund, ensure that you are being completely honest in your dealings.
Let us pray together:
Dear Heavenly Father,
We come before You in Jesus' name, lifting up our brother/sister who is facing this difficulty. We ask, Lord, that You would move on the hearts of the company to take responsibility for their poor quality control and to issue a full refund. We pray for peace for our brother/sister, that they would not be anxious about this situation, but would trust in Your care for them. We also pray for the company, that they would conduct their business with integrity, as unto You, Lord.
In Jesus' name, we pray, Amen.