Should my bill be this high after my contract period has ended?

[Catherine-97]

My 24-month contract ended in September 2023 which cost me £57.64 a month. 

Since Sept, my bill has continued to stay this amount each month, even though I've technically paid off my phone and should only be paying for sim-only now. I'm curious as to whether this was a simple mistake and that I just need a refund on half of the bill for the last 3 months. Can someone please help me find out more?

[MI5]

@Catherine-97 

If on a standard contract the amount won't change unless you make any changes.

If you're happy with the phone you can upgrade to a sim only.

Use USwitch
https://www.uswitch.com/mobiles/compare/sim_only_deals/o2/
Choose the deal you want
This will automatically redirect you to the O2 website
Just follow the prompts and choose the UPGRADE option
Complete the deal and nothing on your account changes except the tariff at the new cheaper cost
Payment date is the same and your next bill will be cat a cheaper rate and will be made up of the pro rata cost of your old tariff and your new tariff
The change should show in My O2 within 24 hours
Volt benefits will still apply as will possibly a 3 month extra such as Disney+