Mr Bolt said April to June for my upgrade (10MB to 20), but it happened yesterday
Now to get the upgrade to 30 MB: Customer Support tell me there's no extra monthly charge, but there's a £20 delivery charge for a Superhub and a new 12 month contract. Got that agreed by Pauls9's budget adviser, called back, got disconnected, called again, got transferred to Technical Support, who couldn't make any changes for 24 hours since the last change.
Ah well, try again tomorrow...
P.S. Could I negotiate better terms?