Cancelling using cool off Period with o2 Switch up

[Rossp]

Due to poor customer service, I am thinking about cancelling my contract with o2, currently I am waiting on a device that’s still processing, I want to get the device from a different provider, as they have the stock, so once I get the device I am waiting on from o2, can I take it to my local store and return it as long as it’s within the 14 day cool off period??

[MI5]

@Rossp 

You can use it now but you may run into issues if O2 haven't acknowledged receipt of your phone from a billing perspective.