Aloha TonyKnives!
Man, that's too bad. The Merlin was one of my EDC's for quite some time. I abused the heck out of it, and it would still be going strong, had I not tried to resharpen it with a Gerber diamond rod! LOL!
There are too many variables here, BUT, I do see your point of view regarding the way they worded their response to you. I'd be pissed myself had I received a letter like that.
BUT, on the other side of the coin, if Sal did look at the knife personally and felt that it was "all used up", than that's that my friend. Sal has got to be one of the most ethical CEO's in the industry, and IF he was the type to not give a $hit about his end line users, I honestly do not think Spyderco would be where they are today.
TonyKnives, please do not abandon or blame ALL of Spyderco for the way one of their Service Reps "mis-worded" their response to you...in a nutshell, that's all it really was...
Please post pics if at all possible. It's not like I do not believe you, but I have never seen a lock back spring pop out! Mahalo for your time, and God bless!