How well have you been compensated in a restaurant for bad / slow service?

4 of us and a baby went out for a nice meal this evening. After 45 mins of no food I checked in to see what was going on. They hadn't put the order through so had to re order all over again. At the end of the meal the manager came over and said the entire bill was comped! Was quite surprised as only expected the usual discount or free desserts kind of thing. Anyone ever had similar? This was in a nice restaurant too, probably £200 bill.