When I was in high school, this is how it went down.
Random guy: Molo sisi, Ndicel' ukubuza.
I stop, nigga comes through ( I already know what he's gonna say but I stop just incase he really lost or something)
RD: awusemhle
Me: (smile) enkosi, what you wanna ask?
RD: what's your name?
Me: *insert real name here* is that what you wanted to ask?
RD: ndiyakuthanda
Me: that's not a question
RD: I know but I said that to get you to stop
Me: so you lied Hhmmmm okay, so what you want?
RD: I want you to be my girlfriend
Me: I have a boyfriend, sorry.
RD: I know that, obviously a grown beautiful girl like yourself would have a girlfriend, but I was thinking that nam ungandinika ixesha lakho, andizokuphazamisa into yakho nomjita wakho.
Me: So you want me ndijole nawe and my boyfriend and the same time? So uzama ukuthi ndisisfebe?
RD: no no no that's not what I meant, I just like you..........(to which I cut him off by saying)
Me: what do you call a girl that has more than one boyfriend, sisifebe right? Hayi let me bounce cause clearly awundithandi that much if you can stand there and insult me like that bye.
(I walk away while the random guy is calling) lol
It worked for the longest time, now that I'm older, I just respond to whatever while I'm walking away.