Why should Openreach compensate you? You're not their customer.
The same way if you take Tesco Mobile and there is a problem with O2's network. Tesco Mobile compensate you, not O2 as you have no contract or service agreement with O2.
In your case, the ISP should be claiming compensation if you have a fault raised with Openreach and it's not fixed within the SLA. For each day a FTTC fault is not fixed within the service agreement (excluding matters beyond reasonable control), an ISP is entitled to one month's FTTC line rental. This is capped at a maximum of 60 days, but that can be worth several hundred pounds.
It is a very reasonable question to ask A&A if they have received compensation for your ongoing fault. If they haven't, why not? If they have received compensation, why has something not been passed on to you?