Why use the whole alphabet?

Me: Welcome how can i help you?
Cust: Mm...
Me: Are you interested in our offers?
Cust: Mmm..
Me: Are you looking for Phone, Internet or tablet?
Cust: Mmm..
Me: All of them?
Cust: Mmm..
Me: Well what company do you have now?
Cust: Vodafone (First intelligible word he spoke! hallelujah!)
Me: We have offer X and offer Y
Cust: Mmm..

And leave without saying anything else..