You buy a phone on a contract with a provider?
That should mean your contract is with the provider. Regardless of OS on the phone, any server provision etc.
The Sale Of Goods 1893 comes under Misrepresentation Act 1967 says goods sold must be fit for purpose.
If your contract is let down by the ancilliary parts that fall under the umbrella of main contract... if failure is evident and unresolvable by your reasonable efforts to follow instructions to remedy, then at the point you feel unreasonable duress lies on you, then that is a failure of your contract.
The issue then becomes do provider instruct the sub providerto resolve or instruct you to approach. They can do latter, but that depends on whether you feel implied frustration or distress from your reasonable presentation of the issue at hand.
If you do, you should insist that the holder of agreement with you namely the contract solves the issue within a reasonable time.
If this isnt forthcoming you can summarily terminate said contract for blamed reasons. Including any felt/implied /unwritten arrivals you get at in thought.
This written without predjudice, obviously.
The case Im thinking of involves a record holding paralympian and Member Of The House of Lords, Tanni Grey Thompson.
O2 politly referred to Blackberry, and the wall Blackberry threw was insurmountable for Tanni.
So in good faith Tanni held the contract, and tried to resolve on deemed reasonable instruction.
On enacting the instruction it became unreasonable in practice. And there lies the reversion back to provider for resolution.
I'd hope that O2 can solve this problem within a reasonable time, which in my opinion reasonable time has expired, due to customer Contact/ instruction to customer/ customer action /solution barrier which lays reasonable time as imposible if resting with the customer to solve.
The liability under my premise laid out is for O2 to replace phone and solve issue within lets say about 48hrs, which under the circs would be a reasonable aquiescence by the customer.
Without any predjudice. My thoughts rest here.
Obviously a 48 yr old act will have later, subsequent amendments notably in 79 and 82.
And theres other more specific references Helen (@complainingcow ) has highlighted many times on twitter)