I would suggest that you are all wasting your time. I have a similar problem with so called infinity 2. Agreed to extend my contract. No increase from Infinity 1 even although my estimated speed said there would be.
In short I think BT are selling something to some customers that they can not provide and the get out clause is if the speed is above 12 then it is deemed to be acceptable. It is a bit like buying a Ferrari and being told it is capable of doing 160 mph but if it only does 12 mph there is not a problem.
As soon as my contract is up I will be taking my custom to a company that can supply the service they are charging me for.
You've summed it all up in a nutshell! I totally agree.
There a few very different situations here, which maybe should have different resolutions.
1) Users of Infinity 1 who upgrade to 2 and find no increase, with Infinity 1 profile under 38.xxMbps, it is clear their upload won't improve in Infinity 2. An actual connection is a much better estimate than anything the BT estimator will come up with. Ideally, the sync information should be available to the ordering process and users should be given very clear warning before they order that speed will not increase. Given how brain-dead the BT ordering system is, that seems overoptimistic. Alternatively, the BT sales channels (online or phone) should make sure that the user is aware of the possibility, and tell them to check their current profile before proceeding with the order.
2) Users of Infinity 1 who upgrade to 2 and get much less increase the estimated. This too could be avoided by looking at the Infinity 1 Max Downstream Rate. This is more difficult because of the Openreach locked modem issue. I don't know how easy it would be to make the Max Downstream Rate available to either users or to sales from the cabinet side.
3) Previous non-Infinity users who don't get near their estimate; maybe because of aluminium lines. Unfortunately, this is much more difficult (probably realistically impossible) to predict ahead of installation. Unlike the Ferrari which is built brand new in the factory, your FTTC connection is coming over lines often installed decades ago with no thought other than to give a poor quality voice connection. It's amazing it ever works at all. BT should be required to emphasise to people that the promised rate is 12Mbps; for example it should be spelt out in "Your broadband checker results". As you will see from many indignant postings, people think the estimate is a promise.
In the first two cases, customers were already on BT contracts. If BT are too negligent to ensure they don't do a misleading upsell, at least when they do they should be required to give the customer the option of returning to the old contract (price and length). The costs to BT of moving people between different Infinity options should be negligable.
The third case is more difficult. BT went to quite an expense to install the deficient service, and though aware there was a risk of such deficiency, they knew that it was fairly low (I've no idea of actual percentages). In most cases, the service, though bad by FTTC standards, is better than the previous ADSL service. I think BT charges the same for its unlimited ADSL package (very bad value compared to the competition) that it does for Infinity 2 (very good value for most people). Maybe a reasonable compromise is that BT should reduce package charges to about 70% for people who are accidently missold in this way. If there aren't too many of them, this won't cost BT very much. If there are lots of them, then BT needs to think of a way to avoid the misselling happening in the first place.
Unfortunately, Sageman will find that comanies that assure the service he wants will charge much more. All FTTC products go through the same Openreach FTTC system, and while they may give better service in various ways than BT, they won't be able to make a huge difference to raw connection speed. Once FTTP is around he may do better (at what price?). For now, the only reasonable alternative is Virgin, and their users don't seem to hold them up as a shining alternative.