ARGGGHHHHH!!!!!!

Deepest, darkest night. The phone shrieks through the silence at 4:38 am, or thereabouts.
"Hello. This is some translation agency in Singapore that you have never heard of. We got your telephone number from the translators' directory. We would like to offer you a job. Oh, is it nighttime there? I don't know. I am in Singapore."
Yes lady, it is nighttime here. Yes you have just blasted me from sleep and nearly given my dog a heart attack to boot. No, I cannot deliver a translation of a business contract to you by tomorrow your time, which will be the end of today my time. No, I do not want to look over the job first before I decide because that would mean getting out of bed, turning on my computer, waiting for you to send the file, reading it and THEN telling you no because I have no idea who you are, if you would ever pay me and YOU WOKE ME UP AT 4:38 AM AND DIDN'T EVEN APOLOGIZE!
I need to train myself to just say, "Thank you for the call but it is the middle of the night here and I cannot discuss business. Please call back during my normal business hours if you'd like to work with me."