New Install - BT Wholesale estimates wildly low

Just had our BT Business ADSL upgraded to Infinity. We could only move to the 40/10 product because the wholesale estimate showed

FTTC Range A (Clean) 42.2 32.4 8.1 5.7
FTTC Range B (Impacted) 35.7 20 8.1 4.3

However, the line is far better than this (according to the HG612)

VDSL Port Details Upstream Downstream
Attainable Net Data Rate: 24804 kbps 72048 kbps
Actual Aggregate Tx Power: 7.3 dBm 13.3 dBm

Is there any way to persuade BT to let us purchase the 80/20 product?

Speak to BT Business Broadband.

Queuing for them now. They initially wouldn't let me order the 80/20 - hopefully they will now the line is active

They are (often) a little more clued up than their residential counterparts. They may need to go through BT Wholesale to have remote tests done, maybe even raise a 'Business Boost' task.

They almost certainly will. When they get a customer with estimates such as yours they will tend to refuse so they can avoid the hassle later on when you say "I ordered 80/20 and am only getting 37/9 (or so) there must be a fault". It is preferable to put you on the slower product and move you up - there should not be any significant change of contract duration except a day or two.

Had you insisted on 80/20 at day 1 against their recommendations, then after install it was found your line would only support 35/7 you would be stuck with the higher costs for the contract duration.

Well they've placed the upgrade order (3 times so far) on this call, but can't tell me how much it's going to be, or whether the order has actually been accepted...

Been on hold for about 10 minutes so far.

Scrap that..
Orders all cancelled and now speaking to someone else who will try to process it..

Their system won't allow an upgrade order full stop.

I've been put through to support to do a line test

Your original post suggests you have had it installed today.

I wonder if the reason for failing is that the job has not been closed off on ALL systems and it needs to percolate through. You may be best waiting until Monday to try again.

No luck - the only test they can do is a sync test apparently which won't help.
They can't place an order 'the radio button is greyed out'.