Electric mirrors

Retracted my mirrors today (silly move ) and now the left hand sucker wont go back. The mirror itself still goes up and down etc. but no back out. I assume the fuse is OK as tother side works and as far as I know there is only the one fuse number 4 I think. It wont force back out as i tried gently and I have the whole shebang hanging off now so I can get grips onto the bottom of the shaft, but so far no give. I've got it soaking in penetrating oil and will try again in the AM.
But if anyone has a bright idea I'm all ears
On the plus side we found that the mirror has heater in it but I don't know how it's turned on

OK if anyone else has same problem the fix is a lot of fun. First take off the door trim, bottom half pops off then after an hour if cursing and swearing you find that you have to push the bloody thing up to get it off. Then you can unbolt the mirror taking care not to drop the screws down into door cavity(like I did). Then pull mirror apart until you can get at motor which is hidden under a plastic cover that is bloody hard to get off. There are a couple of wires going into the little motor bare a couple of spots then using a couple of wires hooked to a battery you can move drive either way by switching the power from one way to other, then you have the fun of putting it all back together all the time telling yourself and and anyone else that is around that if anyone touches that button again there will be death in the family