Restrictions
I've no experience of 3 (my son uses them, but I never have), but this sounds plain silly. I'd be tempted to try escalating, ask to speak to supervisors, or customer complaints about the poor service, maybe tell them that you are not getting the service you are paying for and consider their inability to remove restrictions you never asked for to be a breach of contract - I'm no expert in this stuff, just thinking what might get their attention. Telling them how many times you've been told it will be fixed, if necessary taking it to the media (it's amazing how many intractable customer services problems get solved when they get a phone call from say The Guardian rather than a paying customer, i.e. when it might be about to cost them other business through bad publicity).
But what has changing your browser got to do with the "my 3" app? Surely you can use any browser you like, and change the default browser just by clearing the defaults for the current one, waiting until something opens a web link then telling it which browser you want to use instead?
But what has changing your browser got to do with the "my 3" app? Surely you can use any browser you like, and change the default browser just by clearing the defaults for the current one, waiting until something opens a web link then telling it which browser you want to use instead?