There is also a screw in between the terminal prongs that MIGHT readjust the switch back into range.
The next time you run he unit, do it, until you see frost coming back towards the compressor then just tweak the screw outwards to remove tension on the spring inside until the compressor cuts out. It should not take very much movement of the screw!
Of course, you will have to slip the connector on and off to get access to the screw which stops the compressor each time (unless you have power from some other place coming to it) so use small increments while backing the screw out or back in!

If the compressor fails to do anything different, then the switch has failed to a point out of the operating range and will have to be replaced!

Hope this works out for you either way?
Phil