Airtel — network busy always & voice breaks

Address:

620018

Every time i make a call to any phone no. From other than airtel network, i used to get a recorded voice "all network are busy".

But when i call any no. From airtel network, i get connected immediately, how is this possible

Looks like airtel purposely doing this to their customers because of heavy competitions from other network providers, this is injustice, and this will lead the consumers to shift to other networks, i am also thinking of that