Yeah, unless you're wearing something like an Omega Railmaster or Rolex Milgauss, best stay away from magnets. Even the ones used in knife racks can cause issues.
When I worked for a large bank anything that went the Ombudsman cost £250 in fees, so the complaints team had that level of authority to credit accounts. Cheaper in the long run.
Was that direct from O2 or from a reseller? Direct they lock you in for 3 years but then drop the device part of the pcm when paid off. Reseller it doesn't change after the lock in period unless you ask.
Inflation rises are a sham. If they really needed to increase the price they would increase the new contracts in line as well, but the bastards don't. It's just to pad their already healthy bottom line.