That sounds quite funny, actually. But I can see how it would be annoying to you. I just would be laughing if that happened to me.
Sometimes mishearing people can make for really awkward situations, though. T:
It's the reason why sometime ago, I had my arm around my best friend's neck (she was laughing and knew I wouldn't do anything) and tried to make her tell me what she really said. I still don't know, but she at least confirmed that what I thought she said is incorrect. I actually had to write down what I thought she said, considering it's one of those words that, when heard, everyone listens to hear the rest of the sentence.