hold firm

.... the depressed person's emotional agony had so completely overwhelmed her... that whenever a member of her Support System finally said that she was dreadfully sorry but she absolutely had to get off the telephone, the primal instinct for sheer emotional survival now drove the depressed person to... beg shamelessly for two or even just one more minute of the friend's time and attention, and - if the "supportive friend" held firm and terminated the conversation - to spend now hardly any time listening dully to the dial tone....