I’m sorry about the frustrating situation your faced with porting out your number, I can confirm that Ofcom are correct, once the PAC code is activated and the porting out process begins, the new provider are responsible for any of the errors that may occur in the process.
This wouldn’t be a valid reason for the cancellations team to cancel off the other contracts that you hold, this would be because Virgin Mobile are not a fault if your new provider are experiencing issues bringing your number over to them.
I understand this isn’t the outcome that you would hope for, and I have personal experience with how frustrating it can be when your number port hasn’t gone through properly.
If I can help you in anyway by having a look at the port out from our systems, then I’d be more than happy to. Please let me know if you would like me to take a look and I can private message you for more information.