thanks for update
If you use this checker it will tell what cabinet you are on and what services it can receive.
If it does not show a cabinet number it will be because you are on an Exchange Only line which will mean you can not get Infinity because you are not connected to a cabinet, instead you are connected directly to the exchange.
qq. If you're on an exchange only line (like me) will we ever be able to get Infinity? Is it something on the BT/Openreach road map at all?
people on EO will get fibre as openreach are building cabinets just outside the exchange although that is mainly after the current rollout. If you search through infinity board you will find some where they are now connected and others where the cabinet is/has been erected already