It seems that almost everything you do on the phone or internet now is followed up by a request for feedback asking how good they were. Being a cynic these days I refuse to complete these. Some may well be genuine, hoping to get feedback so they can do better, but I suspect many sell your details on so you can be targeted with junk mail and junk phone calls. So, I just delete these. Call me a boring old fart, but I am not increasing my chances of being a target.
If I get very good or bad service I am quite happy to write an email. Many years ago I wrote to the MD of Dell. Within days I had a phone call back from their head office and my PC was fixed. Sometimes this works. The last thing big companies want is adverse publicity. When you get very good or very bad service you tell people. They prefer you to tell others when things are good.