This should be covered by warranty, so call Samsung and have it replaced. If you're out of warranty you're out of luck because even if you sell it you have to disclose the problem so that it won't fetch a lot.
Do you use 'a' 2A charger or 'the' 2A charger? Only the original charger charges my tab pro 8.4 fast, none of the many other chargers does. With the OEM charger, I think I charge about 50% in 2h.
The Tab PRO is supported by Cyanogenmod. If you don't care for the Samsung extras but want more customization options and much better battery life, this is the one to get.