Negative Marketing

It was long time back when mobile phones were introduced and spread.
I happened to get one Hutch now Vodafone sim card.
In the hurry of daily chores I forgot to top up my balance in the sim card.
When I tried to make an important call a sweet voiced female mildly laughed (she tries to be polite) and in a happy voice declared that I have a low balance and cannot complete that call.
The actual marketing strategy would be that she should politely apologize and gently inform me that I should immediately top up my balance in the sim card before proceeding with the call.
But the laughter which would have gone well if it were to wish me a happy birth day or some happy thing like that and the voice in which she conveyed the position irritated me so much that immediately I removed & threw that Hutch sim card and switched to some other operator the same day.
This is negative marketing.
The tone, the gesture and the way you convey good & difficult things to a customer go a long way in ensuing the continuity of the customer's loyalty to one's product & organization.
With Best Wishes
Mere MBA degrees will not teach such nuances but experience also adds some weight to your actions
All the Best