The UK voted on whether or not to stay or leave. They never voted for the subsequent detail that they weren't told about, the detail that is now becoming apparent. The detail is now is not good, and as a consequence there is now a majority to stay, at least according to reputable polls recently taken. A50 can legally be withdrawn, and any government worth it sort and with leadership and guts, would now do the best thing for the UK, and abandon the negotiations, withdraw the A50, and get on with running the country in the best interests of the population as whole.
There is IMO zero chance that the UK government would seek the revocation of A50 without at the very least a) the conclusion of the Brexit negotiations and the understanding of the deal that was on the table, and b) the rejection of that deal in a UK parliamentary vote. I also believe that even with those two conditions, the UK government would not seek A50 revocation without also c) a second UK referendum whose outcome was a majority for "remain".
On the pre-referendum campaigning issue, it's important to remember that actually neither "side" in the debate ("Remain" and "Leave") really knew what a Brexit future would look like in practice. And in that context, it was always inevitable that the "Leave" side would make Brexit look as rosy as possible, and the "Remain" side would make Brexit look as apocalyptic as possible. I believe it's also a truism that a large majority of "Leave" voters really had no idea what they were actually voting for, and did not have the information or the understanding to figure out the true ramifications. I think a sizeable proportion of "Leave" voters did so out of a combination of the superficial attraction of the "take back control from faceless Eurocrats who are seizing loads of our money and loads of our capacity to make our own political decisions" mantra, the insular (and ignorant) immigration issue, and some form of a prevailing desire to reject the authority of "establishment" political parties (and remember, the official position of the Conservatives, Labour, LibDem and SNP was for "Remain") in favour of "outsider" agitators (funnily enough, I think a very similar psychology drove the rise of Corbyn to become Labour leader, and in turn the better-than-expected performance of Labour under Corbyn in the last General Election).
I think that the decision to hold the referendum was a disastrous mistake by Cameron and his advisers - a mistake for himself, for his party/Government, for the country, and for the EU. I think he (wrongly) bargained that he would go to the EU with the threat of a "Leave" result, use that as a device to radically alter (i.e. improve) the UK's deal with Europe, return to Westminster triumphantly waving his metaphorical Neville Chamberlain "piece of paper", ride to a "Remain" outcome in the referendum as a result of his renegotiation, and cement his place in UK political history as a result (in addition to strengthening his position within his own party, and his party's position among the electorate). I also suspect that the original 1970s referendum on entering the EEC was probably a significant factor in the decision to put the "Leave"/"Remain" decision to a referendum, rather than (as should have been the case) leave it entirely in the hands of parliament (whose lower house is, after all, elected to represent the population....).
Disclaimer: I was (and still am) a strong proponent of "Remain", albeit under different terms and under a significant reorganisation of the EU as a whole.