First, I think you should go back to Best Buy and argue your point and go as high as you can to deal with upper level management because you think you were duped into buying it there because of the one time fix. Also, take up your issue at an Apple store, again, only dealing with management. If neither works and you have to pay, consider this.
If you repair your ipad through Apple it can cost as much as $299.00. Gazelle.com will give you $60.00 cash for it and they pay shipping. Prices can go down, so if you decide to do it, act fast. Not all online trade-in companies take broken ipads. Google it and see if other companies will take in and/or pay you more.
Then consider the Apple online refurb store. A refurbished ipad 2 16gb is $319.00 - then subtract the $60.00 from Gazelle and you'll pay $259.00, probably less than Apple's charge to fix it. A 32gb is $399 minus the $60.00 from Gazelle and you'll pay $339.00, etc.
A refurbished ipad 4 retina 16gb is $379.00 - $80.00 more than a fix minus the $60.00 you'll get if you sell it as is. So for the cost of the repair and trade-in for $60.00, you can get an ipad 4 retina 16gb for $319.00. A 32gb is $449.00. If you subtract the cost of a $299.00 repair, the additional cost to you becomes $150.00 Subtract the $60.00 from your trade-in, and you'll pay an additional $90.00 for a retina 32gb.
Refurbished ipads come with new front and back covers, a brand new battery, and a full one year warranty. They come in the white box with the cable. Shipping is free. iPads come adn go on the site, so when you see what you want, you should buy it then. We have 2 refurbed ipads and they have been great.
Hope this helps.