The dilemma being, though, that a lot of people who voted "Leave" now seem to feel they were duped
Well, the vote was to stay or leave, and they voted to leave, and now the UK is leaving.
If they felt they were promised immediate prosperity, or whatever, then I don't really know what to say about that. Generally, you can count on your opponents in a referendum such as this to make extensive note of any downsides, so it's not like voters were never told that there would be penalties for this as well as benefits.
And there is the precedent that several countries in Europe has second referendums on entering the EU after the first referendum ended in a "NO" vote.
Very well. If the second referendum was held because someone didn't like the results of the first then I have a hard time supporting that either. If it was years later (different electorate, different times) then fine, no problem. But to turn around and re-vote on something you just voted on doesn't really seem legitimate to me. Again, what makes the second vote meaningful if the first was not?
ed'd to add: for what it's worth, I personally think this referendum would have been a perfectly appropriate time for a supermajority requirement. This change -- Brexit -- is going to have an impact on nearly every segment and sector of UK society, and cannot be easily undone.
I say this knowing how unpopular supermajority requirements for referendums are. But if they'd had one, we wouldn't even be talking about this.