Issue here is your bank has verified what a/c numbers hes given you and what you have paid into.
Hes definitely given you the right a/c number- you've gone back and asked him to reconfirm?
So the money is in his banks system. His bank isn't obliged to give you any information at all. Which means it has to be driven by him (with permission from him/request where the funds are). If hes not forthcoming with this little bit of human-nature then I would honestly involve the Police now.
Even if he geniunely hasn't received it any decent human being would investigate where its gone. Initially I'd think you were trying it on with me but with your insistence I'd start digging, phone call etc. At the very least I'd do this- partly to close off the subject and put it to bed eitherway/get rid.
Can take upto two weeks- Sorry. I really don't believe that in this day and age.
Sorry, I'd involve the Police now and say unfortunately you feel you are the victim of a fraudulent transaction that didnt involve anything to sell. It can't be doing your blood pressure any justice.
What if this seller is actually doing it to others and turns out to be a teenager laughing his head off in his parents house? Far-fetched I know. Still.
Would I wait two weeks for someone to say 'no mate, nothing received'? No. Be proactive now. I wouldnt worry about him suddenly ignoring you- doesnt sound like hes being bothered anyway. Police involvement would make him sit up.
Call his local force to start with.