Why has my sim only bill increased suddenly more than double in price

[John_Fortune]

Hi can someone help please. My contract ended for my phone last year so I opted for a sim only. On the My 02 app it says I can upgrade today so I've been looking at upgrading my phone. I've sent PAC to get a pack code and the message I got back was that I'd still be charged a fee of £321.24 wtf. 

My sim only was costing me £15.20 a month for unlimited everything and now its jumped up to £44.26. Why, and without notifying me. 

This bill is on my current phone Samsung Galaxy S9 hence why I was looking to upgrade it today because for that price I can get a newer phone and I'm not happy with paying £44 for a older phone. 

Please help, there are no extra charges on my bill, just that its jumped upto £44 from £15. I wanted to upgrade but I'd still be charged the £321.24 right

[MI5]

@John_Fortune 

You don't need a PAC to upgrade from a simo  to a phone.

You can upgrade without any penalty fees at anytime.

[John_Fortune]

Thats what I don't understand. I got the pac code just to have incase I moved over to another network coz of the price jump. I don't understand why my sim only has gone from £15 to £44 and with no notification of the increase. It states that I'd be charged the £300+ if I upgraded today but I paid off the contract in full last year. As I thought a sim only package I could upgrade anytime, are they saying I've got to pay off the sim only payments like a contract phone? And why is my sim only bill gone from the £15 to £44

[MI5 · Accepted solution]

You only have to pay if you leave O2 @John_Fortune 

As for the price change, you'll need to ask O2 why Guide: Coronavirus Community Help and Support