Mate, I have felt the same way at times. But - and here is the nub of the matter - on average, and taking into account everything I see and hear, Nikon reliability is about the same as Canon, and the service can be a good deal worse. I also think of switching back to Nikon sometimes, but then I look at the tales Nikon owners tell and after a while I settle down and realise that I'm still better off where I am. It's not perfect, but for a bird photographer, it is the best choice in town.

What you need to do:

1: Take a series of formal test shots. Use a good tripod, mirror lock up, and 10 second timer. Document your exact steps. You have demonstrated faulty goods, you want them fixed, please.

2: Send that documentation to Canon with a written request that they rectify the problem. Be polite but firm.

3: If they do nothing, send it again, this time also send a copy to consumer affairs as part of a formal complaint. Document that too, and send copies of everything to both Canon and CA - i.e., make sure everybody knows what you are doing and what the consequences are.