In order to find out what services and speed range you should be getting, please enter your phone number into this form.
Broadband availability checker
Please remember to edit out your phone number before you post the results.
Which BT home hub are you using?
Could you please post the results from the BT Wholesale speed checker, including the further diagnostics.
What does the checker show, you can do that from your phone. What speed were you guaranteed when you signed up for Infinity2?
The Broadband availability checker is not a test, it will give you your estimated line speed. Ordering Infinity 2 won't give you 76/20 unless your line will support it.
Enter your phone number into the checker and post a screenshot of the result. Remember to remove you phone number before posting.
You will need to display the information from your home hub, but that has to be done from a computer.
You can use this direct link from a computer.
Your upload connection speed is 10Mbs, so your actual upload speed, peaking at 6Mbs, is about the best you are going to get.
The BT Wholesale speed test will be a better indication.
You are wasting your money on Infinity 2, as your line cannot support the speed.