We are truly sorry to hear about your pain and difficulties. We will stand with you in prayer, seeking God's will and intervention in your life. Remember, God is always with us, and He cares about even the smallest details of our lives.
Firstly, let's pray for your healing. God's word tells us that Jesus took our infirmities and bore our sicknesses (Matthew 8:17, WEB). So, let's agree in prayer, asking God to touch your throat and relieve you from pain.
Lord, in Jesus' name, we come before You, asking for Your healing touch upon this dear one. You are the God who heals, the God who makes all things new. We ask for a miracle, that this sore throat may be healed, and the pain alleviated. We believe that just as Jesus went about doing good and healing all who were oppressed by the devil (Acts 10:38, WEB), He is still the same today, willing and able to heal.
Regarding your father, it's important to remember that God's people should do all things decently and in order as well as making requests in a respectful manner. Nowhere in the Bible does it say to avoid discussing important issues with family. (1 Corinthians 14:40, WEB) As for the online seller, we should continue to pray for patience and guidance. God's timing is always perfect, and we should trust Him even in the small things like this.
While we agree that God can work miracles in your life and circumstances, it’s essential to remember that Jesus tells us and this is His Word from John 15:16, (WEB), “ You didn’t choose me, but I chose you, and appointed you, that you should go and bear fruit, and that your fruit should remain; that whatever you will ask of the Father in my name, he may give it to you.”
Therefore it is important you are asking in Jesus' name and not in your own name or by itself. Also, if you are not obeying His will then God is not obligated to grant your requests. Also, you have not indicated that you are a believer or have a relationship with Jesus Christ. This is the basis for all prayers to God. You must believe in Jesus to ask in His name. For further discussion or questions on this, we are here to assist.
We will pray that God works in your father's heart and the online seller's heart, that they may be willing to help you. But remember, God's ways are higher than our ways, and His thoughts higher than our thoughts (Isaiah 55:9, WEB). Trust that He is working everything out for your good (Romans 8:28, WEB).
Finally, let's pray together:
Heavenly Father, we come before You, lifting up this dear one to You. Lord, we ask for Your healing touch, Your guidance, and Your provision. We ask that You work in the hearts of their father and the online seller, that they may be willing to help. We ask for these things in Jesus' name, believing that You are able to do exceedingly abundantly above all that we ask or think (Ephesians 3:20, WEB). We thank You, Lord, for Your love, Your care, and Your faithfulness. In Jesus' name, we pray. Amen.
Prayer Focus: God, Thank You. Thank You for loving me. God, I ask You in Jesus’ name bless me with everything that I stand in need of and everything You want me to have. Bless me to know You in truth, fall in love with You with all my heart, mind, soul, body, and strength and never fall out of love with You. Bless me to have an ever growing closer stronger, more intimate relationship with You. Bless me with the love, desire, strength, and the spirit of obedience to always delight myself in You, seek first Your kingdom, and Your righteousness. Help and strengthen me God to always respect and obey You. Bless me to trust You with all my heart, acknowledge You in all my ways, and lean not to my own understanding. 
