I think there might be a bit of confusion going on in this thread (or I am the one getting confused!) due to so many products having so many SLAs with similar sounding names!
There are various SLA's offered by Ovenreach which cover PTSN line faults -as laid out
here - the highest SLA (Level 4) targets a 6 hour resolution time.
Then, there is a separate ‘Enhanced Care’ product which covers broadband issues. It is what A&A, Zen, Plusnet etc all also resell. It aims for someone to initially respond in 3 hours and to solve a broadband issue within 20 hours (but this is not guaranteed). For some reason, I have a vague memory that its actually a BT Wholesale offering not a Openreach one..
Edit: If keeping in touch is important, the best combination is probably a PSTN voice service with an Openreach Level 4 SLA - but obviously its not something A&A offer. I know A&A don't supply voice lines but don't know why they don't seem to offer the enhanced PSTN SLAs to their customers.