Personally, it sounds like that tank was not being taken care of properly in the first place. What if all that stressed a fish and caused it to die? What if your water quality prior to this was the cause of death to a fish and THAT caused the downward spiral of your already problem tank? Would it not have been wiser to have RCA come in much earlier to do service? To me it sounds like you are looking for a fall guy, and Carlos is it. His manner in the letter is completely appropriate, and after a week of being gone, it is next to impossible to say that the rock was the entire cause of your tank crash. Did you forget to leave the A/C on, and one day, your fish died? There are too many ifs ands or buts from your side to determine that RCA was at fault in any way. Welcome to MAAST, sorry for your bad experience, and thank you for handling yourself the way you have. You do have every right to be upset, but most people cringe at leaving their tanks for days at a time, not a week. Who fed your fish?