Curtains destroyed and poor attitude from owner and manager

I took curtains to Sofisticlean for cleaning. They managed to melt the curtain rings leaving black smears all over the curtains. Sofisticlean refuses to acknowledge any negligence and the manager just says they have a procedure and I signed the slip. The owner just shrugged his shoulders and said too bad. I took the curtains to a professional and they cannot be salvaged and will have to be replaced .