can I know who is t-pot computer? Is that a distributor for PC parts? Or are they brand name? How can you just send the board blindly back to them? Shouldn't you have called first to confirm the situation?

it depends on what is the deal. IF he is selling as a sales man from his company, then he don't need to be responsible as the company will be responsible. But if he is selling personally then he must be responsible. That means if he made the profit directly, he must bear responsibility.

I agree with Pip_X. Seller is selling on behalf of the company. When he left the company, he is no longer responsible for any transaction related to the company. Heck, if he does help and something went wrong, he could be sued by the company.

Please get your facts straight. Your case is with t-pot company and not the person you dealt with. You should seek the person who replaced seller to handle your case. If you don't get satisfactory help, it's the fault of the company. It's not right to put the burden on the seller who already resigned.