That's all too easy to do! If you end up flattening the end of the pin and manage to get it free it still won't do any good there. A flattened down end won't fit back into the plastic molding. The entire plug with then be scrap as far as normal use is concerned.
The idea is to see if you are able to give it a light twist in either or both circular directions to gently break the hold in order to extract it without damage. If you are able to get it free and intact you may be able to sweat some type of adhesive not epoxy into the hole in the plug itself to secure it and keep from seeing this again.
Otherwise without enough of that type of plug included with the supply your option would be to cut and splice one from an old beat up supply to see it replaced. Black tape likes to unravel when it gets warm then cold then warm again leaving a sticky mess on surfaces you won't want to see.

GGrrr..!