Cancelling a contract which hasn't arrived yet

Hi, I recently ordered a 12 month sim contract which I want to cancel. I originally ordered it due to having issues with my WiFi connection but I’ve recently fixed my WiFi and so don’t need the sim at the moment. The Sim is still in delivery and hasn’t arrived yet, I would like to keep the sim in case I wish to purchase a contract in future I wouldn’t have to wait for a new sim to arrive but I would like to cancel the current 12 month plan which has started (even though the sim isn’t here yet). Live chat is closed at the moment as the offices are closed at this hour, is there anyway to cancel it ? In terms of early cancellation there should not be any cancellation fees as I believe there is a cooling off period/14 day grace period from the start of the contract to cancel without incurring any fees, I read this on the iDMobile site.