Consumer Protection Law
Consumer Protection Law Questions? Ask a Lawyer Now.
Legally, the seller breached from what you mentioned and agreed to make repair without cost. Now for some reason it wants more money which is a breach of agreement and likely implied and express warranties.
You can pursue this by demanding seller honor its obligations as mentioned above, and if seller refuses, you may threaten and pursue complaint with the attorney general office and small claims court, as well as contest the charge with your credit card company - which is called a chargeback
Kindly let me know if that is fast and acceptable, and if I may clarify anything.