I hate to be a pedant but:-"Referendums is logically preferable as a plural form meaning 'ballots on one issue' (as a Latin gerund, referendum has no plural). The Latin plural gerundive 'referenda', meaning 'things to be referred', necessarily connotes a plurality of issues".

"Referenda have no place in a parliamentary democracy." This is a valid proposition but sadly the UK has had 12 referenda in the past

https://en.wikipedia.org/wiki/Referendums_in_the_United_Kingdom
Therefore a referendum definitely has a place within the UK system of government by virtue of the fact that the precedent has been set.
However the recent referendum has exposed some major weaknesses in the present system. Prior to such an event Parliament should enact the required legislation to make the result binding. Because dodgy dave was so cocksure about the remain vote winning nothing was done to cater for a majority vote for leaving. The entire exercise was a tragic comedy of errors and rank incompetence.
   My feeling is that on major issues a referendum is the correct way to go, otherwise the ruling party and their whips can exert influence and sway the vote. Anyone that believes the average politician is more concerned for his electorate than his sinecure is barking mad.
If all politicians were men of integrity and not careerists I could perhaps accept that the need for a referendum was negated as the required mechanisms to vote exist in Parliament.
However in the real world, the lobbyist, party whips, revolving doors, etc, etc inevitably exert a negative influence and a vote predicated on concsience may well be as rare as angel dust.