Thought I'd update you guys.
In the end I never had to take the bezel out, I started with removing the magnet with the plan on removing the bezel/switch if it didnt solve the issue.
Anyways there was a little oul within the magnet area. Cleaned it all with isopropanol and put back together. Seemed to work other than it quickly heated up and started to warm my hand nicely. So I took apart again and them put back together but put the little cylinder (the part that sits in the middle of the magnet) in the opposite way, then was all sorted.
Not sure if it does have to be that way as it does look symetrical or whether I'd not tightened the locking nut enough.
Either way its all sorted, so thank you for all of your help.