it's too late, isn't it

so today my office had the birthday celebrations. they said my last name wrong. i've worked there for 3 1/2 months now, so i feel as if the time to correct someone on how to say it has passed. reminds me of that friends episode where chandler never corrected the guy in his office that his name wasn't toby, and then like five years later he still gets called that. except this is my whole office, not one person. oh well. at least no one uses my last name all that much.