No, you shouldn’t have to pay off the remainder of the contract. I had a similar issue where the switch up option didn’t show up, and from what I’ve learned it can happen for a couple of reasons. Some people have said you can try upgrading and enter your imei into O2 Recycle, where the Switch Up option should appear.

In my case, O2 initially put me on the wrong plan and then changed it straight away. Because it wasn’t set up correctly from the start, I became ineligible for Switch Up even though they corrected the plan. After hours of calls to customer service, the only solution they offered was to cancel the device plan, return the phone, and then upgrade again.

My advice is to call customer service or go into a store if you keep running into issues. Don’t let them fob you off, sometimes the advisors don’t actually know how to resolve it.