How are you connecting the card to the computer? An internal card reader on the computer or an external card reader and cable? The cable may be the limiting factor. Older, simpler cables just can't handle higher data transfer speeds.
Although you may have bought it with good intentions, you are in possession of stolen goods...it is not legal. And the policy of DJI in this regard is to help mitigate drone theft. Did you report the seller to ebay, did you leave feedback? The...