Amalgam fillings removed replaced with resin now they hurt!?

I had a small crack in my amalgam filling tooth 18 back molar.Also tooth 19 amalgam filling had small fracture.Went to my dentist and she suggested to drill out amalgam and put in composite fillings.She numbed me up and it hurt like hell when she removed the silver fillings,she had to actually numb me up again! It also hurt like hell when she put the new fillings in.I have had root canals,apico,lots of fillings and I NEVER had any pain at all while I was numb.Now it has been a week and I am still in pain.They said give it a few weeks it will be fine.My question is do they remove these amalgam fillings on a regular basis to replace them? I really think I needed a root canal.She only took pictures of the tooth to see the crack not X-rays to see how far down my original amalgam fillings went.What should I do?