Yes, you should be well-pissed off.
But what can you do about it? Maybe not much. If you think it will get done now, then see if they offer you anything, and if not then when it comes to payment time, express your thoughts and see what you can squeeze them for. If you're not sure they're going to get round to it anytime soon, then find another garage that can promise to do better, or do the top end yourself. It's really not that hard, and if you get stuck I'm sure people on this board will be happy to help.
If you've got some tools, patience, and a digital camera and can post pictures with your questions then I would say, give it a go.
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MC28 SE -sold-
MC21 with RS250 engine -for sale-
MC21 race bike -soon for sale-