Furious - IT Support Imagination Technologies Employee Review

Having been repeatedly told about promotions that haven't materialised, I'm just done. "We can't promote you because we would need to give you more responsibility and we can't do that because your current work is too important" is just game over. I was so supportive for so long but I've been here 3 years and I have not been given a job I couldn't do with my eyes closed. I've desperately volunteered for every oppurtunity and challenge and I'm yet to be given anything to the point that my CV looks no better than when I joined.