I have no idea why this is bothering you so much. As I said previously, there is no upgrade possible to increase your speed, ergo nothing was done or could be done.
Because it was a mistake and you shouldn't have received it? Has been known to happen. Hence one of the mods marking message 7 as the solution.
Not sure how many times more I can say this. Your speed cannot be improved with an upgrade other than providing full fibre to your house.
@WorriedParent wrote:
In which case, why did BT send me a message to say they would be improving my speed?
It could be a fake message appearing to come from BT. Did you have to respond in any way to the message?
Just reading the message would confirm to whoever sent it, that your mobile number was active. This is a common tactic used by spammers, so you may get more of these types of messages. I usually delete messages from numbers that I do not recognise.
I can assure you that whatever has caused your slight increase in speed was not due to an 'upgrade'. It was probably due to a fault being cleared or a crosstalk disturber ceasing their service.
It is possible that is what happened, but I would have expected to have seen a larger improvement than the one you have experienced.
If you enter your phone number in the checker https://www.broadbandchecker.btwholesale.com/#/ADSL it will reveal the exchange and cabinet you are connected to. Unless you know which cab you were connected to prior to the speed increase you won't know if your cab has changed however.
Post the cab and exchange information (but not your phone number) and it might give us some clues as to whether it is an infill cabinet.