Bad service

Took my family to Dros Kempton for my daughters birthday. The waitress took 30 min to bring our drinks which she got wrong. Starters took an hour. Mains took 2 hours and my mom got her food 3 hours later. When we get the bill there are drinks on that we never recieved. When we complained to the manager he tells my father he will "sort it out when you stop talking". Never had such bad service at this restaurant. You lost alot of customers last night.