Don't even bother spending your time on someone being this rude to you, while all you did was try to help by offering your service... I would've said fk it, goodluck on your own as soon as i read his reply LOL
Try to dig deep into your past and find as much information as you can find. Me for example found a youtube video of me playing the account which i sent to jagex together with prove of me being the owner of that yt account :P