So, the government can hold a national referendum but if they (the political and social elite especially) do not like the result they can just ignore it?
If it is an advisory referendum, yes of course they can. The referendum is there to gain a snap-shot of the opinion of the electorate. If it is an advisory referendum, then parliament then needs to decide what course of action it should take in the best interests of the country. That is why parliament is sovereign - wasn't that one of the siren calls of the Brexiters, that the UK parliament is sovereign.
You must ask yourselves, supposing the result had been to stay and the losers were wanting a re-run. What would your thoughts be?
Well of course they were - don't forget that Farage pronounced that a 52/48 in favour of remain would be unfinished business.
But there is another point here, where there is a change and a no-change option. I think that there needs to be a greater requirement to be convinced that the change option is the clear and settled view of the electorate than the no change. This is why many organisations either have a higher threshold for change (e.g. 60%), or require the change option to be agreed by simple majority but in more than one place - e.g. acts of parliament requiring passing by both HofC and HofL.
So in this case, given that there was no higher than 50% threshold I think it holds true (given that this was an advisory referendum) that the change decision should be agreed by both the electorate in the referendum and also by parliament with each decision made independently.
And this is where the whole process has been the wrong way around. Parliament should have voted to leave, decided on the nature of that brexit settlement and then put that option to the electorate. That's the way around it is in most referendums, but not in this one where parliament didn't (and I suspect still doesn't) want to leave but is now boxed into a corner created by the ineptitude of our out-going PM.