Increment was in contract , and mine (long time ago) came with a 10 year table of increments with salary total. Probably long since amended out ?There is something there that says they can vary the terms with a notification without amending contract . Then becomes a totally one way contract , dont know how they can hold you to it when they want to , but in the present climate i guess its their trainset ! Only option left is take it or leave it , but feel sorry for those that had options and left acceptable jobs (in hindsight) and are now stuck. Keep discovering !!!