HDFC Bank — personal loan - why calling to my family members for my loan

This bank is sending sms and calling my brother for my personal loan number. 47091399

I don't know why these days they are doing like this.
Till time i have not missed any emi due date.

Only delay happened in one time for 7days in last emi and for that they charged 923 rs as over due charges. I paid it after receiving sms from my brother.

Sms they are sending to my brother and calling him for over of 7days delay.
Shoking, why they are calling and texting to my brother.
They are not informed me by sms.
Why they are doing this kind of work.
I was lost complete trust in this system.