We had a new boiler installed recently and there followed a night of no heating or hot water as the installer left a valve closed (or something very small but enough to cause system to overheat and crash). I filled in a very negative comments card.
Several days later a salesman manager turns up to find out why, gives no apologies and says 'I don't want to threaten you but unless you fill out a positive comments card now I will be back again to find out why'.
Should I complain, or just leave it (as I'm not keen on confrontation, and really would not like to have him back in my house).