Ofcom broadband speed checker (https://checker.ofcom.org.uk/broadband-coverage, enter postcode and select explanation) defines broadband speeds as
Standard, superfast and ultrafast denote different broadband speed categories:
Standard broadband has download speeds of less than 30Mbps;
Superfast broadband has download speeds between 30Mbps and 300Mbps;
Ultrafast broadband has download speeds of greater than 300Mbps;
So 24Mbps is below their defined standard fro superfast.
What we need is for Ofcom to make ISPs charge only for teh speed delivered to the house. Then maybe Openreach would have an incentive to improve the shoddy service in some places as they would be able to make a business case for it where at the moment none exists as they get paid for delivering a type service not a standard of service.