Cancelling in the 14 day cooling off period (Vodafone sim only contract)

Hello
I have recently joined Vodafone from EE but the 4G doesn't work well enough to meet my requirements, so I want to cancel in the 14 day cooling off period. Thing is I have already transferred my PAC code to port my old number to Vodafone and I have been advised by Vodafone (and EE) that this process is now locked and unable to be undone - it takes effect Monday.

When my number transfers I want to get a PAC from Vodafone and then port my number to another network, but I am under the impression that issuing a PAC begins a 30 day period but the cooling off period is only 14? I've never done anything like this before and don't want to be locked into this Vodafone contract; I'd be grateful for any advice I could get