If the crank moves during the belt tensioning process, then you are doing it wrongly. Is the cam sprocket loosened on the shaft?It should be. Did you rotate the crank a few degrees counter-clockwise and then back to TDC without going past so that all of the slack is in the tensioner area? You should have. Pump pin should not be in place when tensioning the belt although there is usually enough slop in the pin that it doesn't matter.
...BTW your Bieber avatar is awesome.-Malone
Please do not use the cam lock tool to loosen or tighten the cam sprocket bolt. You will eventually break the cam. Hold the cam sprocket with something.
A punch is what I use. Just make sure it is a flat punch, not a point! One good whack is all it takes.
Use a bigger hammer or take a longer swipe at it. Unless someone over torqued it, it will come off but it takes a quick sharp wack.