Sorry, that was poor of me.
I took it back the next week as I said I would, and picked it up that night. It had been tinkered with for sure, but the squealy noise was still there, and now there was a rattle under the bonnet whenever I changed gear forcefully, or went over big bumps!
That pissed me off no end, so I wrote a letter to their Customer Service dept, and CC'd it to Ford Australia's Customer Service. After about 4 working days of not hearing anything, I called their CS dept to find out, and she was very apologetic etc. Anyway, the car was booked in and they gave me a loaner (Focus) for free. standard stuff.
They had the car for two days, and when it came out it was fine. Apparently, the new timing belt was faulty because they just replaced it, and the rattle was caused by the engine not being bolted on properly or something small and simple like that...... :(
Never going back there for sure.
Oh, and the power loss issue I solved myself when I was forced to fill up with regular unleaded instead of the Optimax I've used for the last few years. Power came back straight away. I've used Optimax in the next few refills and the power's been there as well. So maybe it was just the computer needed a kick in the pants or something to get it to do it's job properly.