Ipod pro firmware can't be upgraded

i bought a apple ipod pro 2 ,it had a older version of firmware and i was not able to update to latest firmware so i can't do certain action's ,the seller says that you can't upgrade this Ipod ,it was not mentioned in the selling description that this can't be done and now i can't return this item because the seller says that this item is not returnable so is there anything i can do.