Aunty, you called the wrong number

Some auntie called my number 
Aunty : Hi is this Cathay?
Me: No it's not, you got the wrong number
Aunty : May I speak to Cathay please?
Me : There's no Cathay here, you got the wrong number
Aunty : Who's number is this then?
Me thinking *Why the heck do you want to know??*
Me: This is MY number. You called the wrong number.
Aunty : This is not Cathays number?
Me : No, you called the wrong number
*Then aunty hung up*
..... How many times must I tell you "WRONG NUMBER" before you understand???