Why doesn't brokerage firm restrict my account?

I received a regulation T or Fed call on my account from Scottrade twice in the last 2 weeks. I held too much equity overnight each time and it resulted in Fed Calls. I was told that I must deposit money and cannot sell stock to cover the call or I will get a 90 day restriction on account. I sold stock since I had no other choice. I had a discount broker a few years ago that restricted my account the 90 days after the first time. I realize they probably want the account to not be restricted so I can trade and they make commissions. My account at Scottrade still has no restriction. How am I getting away from this 90 day restriction when I was told my account at Scottrade will be restricted for 90 days?