Both my partner and I are with EE. But recently she had an email telling her that her £10 per month deal with 2 gig of data to a 30-day rolling contract with 5 gig of data for £15. She has an iPhone 11 and I have an old iPhone 8 and I am on £9 per month with a gig. We certainly do not need the extra data.
So, she rang them and threatened to leave and lo and behold they reduced it to £12 per month but gave her 10gig of data.
Mine is due to end in October, so I will be ringing them too. Or I might go to pay as you go SIM as I just do not use my phone enough.