I wish to cancel my Orange contract and go onto PAYG. I wanted to escape
paying for a 13th month but I'm half way through the 11th month and
expected I'd have to give 30 days notice and pay part of month 13.

I called Orange who asked me if I would like to go onto Orange PAYG. I
said this was fine and they said a SIM card would be sent out. I asked at
what point my contract would be considered closed and they said as soon as
I call up to activate the PAYG SIM it would be cancelled with no more to
pay.

Of course I don't expect to be able to cancel before the 12 month minimum
term was up but it sounds like they were saying I could avoid the 30 days
notice by switching to Orange PAYG.

If I call on the day that my contract ends once I've received the SIM am I
really going to not give 30 days notice to cancel the contract?