If you look on ITV X or iPlayer, there are literally tens of terrible straight-to-video romantic films with "Christmas" in the title. I imagine they cost almost nothing to license.
I'm well aware of the genre, but it would be slightly unfair to lump Last Christmas in with those. I vaguely recall it being a well publicised cinematic release a few years ago and it even has proper A-list stars whose names you'd know - including Emma Thompson, who also co-wrote it.
Of course, if I cared about the Wham thing, I wouldn't have made the schoolboy error of even starting to watch a film called Last Christmas, but I thought it might be a suitably untaxing way to pass an hour or two while waiting for the call from my son to be picked up from his night out. Was expecting something of the Love Actually level, but it's way more inane than that. Lost my patience with it very quickly.
Without wishing to spoil it for anyone who has it on their must-see list, the premise appears to be basically a literal interpretation of the song's lyrics.
Also heard a cover of the song on 6music this morning - had to go out before it finished so didn't catch who it was by, but it was one of those affectedly ironic takes by some rock band that are so very irritating.