I spoke to the practice manager once with a complaint.
I had made an appt. for dh; had to wait some time for the appt. and made it around the time that suited them rather than us - just grateful to get one at all really!
He duly arrived on time having taken time from work and they denied all knowledge of it with a 'tough luck' attitude and implied the appointment hadn't even been made in the first place. It wasn't the error that annoyed me so much as the attitude. The thing is they are not the only busy people in the world pushed for time and resources.
The practice manager was very apologetic etc and blamed the error on the new computer system (ho hum). He didn't have much of a leg to stand on with regard to the attitude problem though, and said he would 'have a word..' I haven't noticed anything much has changed there since though.
When I worked, we had to introduce a new computer record system for a very big university (larger by far than my local doctors surgery) and there were a few hiccups in the beginning. I too have dealt with difficult members of the public, (students in my case) but if anyone where I worked had come across with such a poor attitude, we would have been in for the high jump because of it!
It worries me though to make too much fuss with the receptionists, because with five of us in the family, I have to use their service quite regularly and don't want to be seen as troublesome or I'll get a worse service, I suspect. The nurses and doctors however are wonderful, once you can get to them.