"validity check ... on payments"
"The only validity check they'll do on payments is to query whether the contract seeks to exchange the sort of thing that contracts may concern."
Maybe you haven't noticed, but for the last year or two the UK High Street banks have been refunding excessive penalty charges for overdrawn accounts, simply because the banks were scared that the courts would tell them to stop excessive/penal charges if a test case went to court and set the wrong (for the banks) precedent.
The banks finally plucked up the courage to take a test case to court, and the verdict on whether the charges were penal (and thus unenforceable under the Unfair Terms in Consumer Contracts Regulations) is due Real Soon Now.
£31K sounds unenforceable too, regardless of whether the bloke's a prat.
Incidentally, if text message can be delivered within minutes between cooperating networks, why does it (allegedly) take days weeks or months for billing info to be forwarded when you're roaming?