Hearing Loops

I'm not sure if this is the right forum for this....I've noticed that whenever I shop in Marks and Spencer, they rarely if ever have a member of staff on the till where the Hearing Loop is situated. I've emailed, written, complained in store and been promised time and time again that they will make sure in future that there is a staff member on those tills. Needless to say, nothing has changed. I've been fighting this battle with them for about 3 years! To add to the problem, the staff never know what the loop is, or what it's for. Can I ask if others here have experienced the same problem and if so, can you add your complaints/comments to M & S?

I've also only just discovered that my GP surgery has a loop. It wasn't switched on, plus none of the staff knew what it was! Frustrating to say the least!