What is a dust bet?  Everyone knows (or should know) that each roll of the 'dice' is independent of the next.  Just because you've had 10 small bets in a row that lost doesn't mean the next large bet wins.  If dust betting is also meant to consume the 'bad' rolls so you can use the 'good' ones then it's the very definition of the gambler's fallacy.

Regarding small bets being resolved instantly but large bets taking a second or two, I've had situations where betting 0.0001 btc also lagged.  Sometimes the lag stretched out to 5 seconds.  Very loose correlation is not evidence of causation.

Without real evidence that JD has done something wrong apart from 'I feel', 'it appears' and 'it's strange that' kind of evidence it looks like you're not getting anywhere.  Even if you create a new account and bet proportionally much smaller amounts on JD and consistently win that of course is not evidence that JD cheated you before.  You need real evidence.