Ameritrade - I'll give you one better. This was probably 15-20 years ago or longer. I had maybe $25,000 in my account and not much more to my name.
I logged in and the account balance was a huge negative, showed up in red, it was something like -$572,878, or some ungodly figure. I nearly had a heart attack, no kidding. Shortness of breath, panic attack, started thinking I was gonna have to file bankruptcy, etc. Calmed down after maybe 15min and gave them a call.
The guy was totally nonchalant about it. "Oh yeah, looks like some short-selling trades from someone else's account got incorrectly attributed to you. Not a big deal. I'll make a fix. Should be cleared up by the end of the day."
As you can imagine, I tore into the guy. "Not a big deal?! Not a big deal?!! How can you say that?! This would totally wipe me out and I'd have to file bankruptcy! It may not be a big deal for you but this is a huge deal for me! You just made like a $600k error and you expect me to take your word for it that all is well?!
Got a supervisor on the line and just excoriated everybody, and I'm normally a very mellow person. But this would have wiped me out entirely, so no Mr. Nice Guy on this one. I couldn't believe how cavalier they were about the whole thing. What if I had been on a two-week vacation and away from computers the whole time? Most of these brokerage agreements are so one-sided they say you have to dispute within like two weeks or else lose your right to dispute. What if I was gone and never had a chance to see the error? I've been VERY cautious of brokers after that.
So in a weird way, I'd say at least be glad you were on the positive ends of things. Think about the poor guy who has $300k missing from his account.
I moved nearly all my money away from Ameritrade shortly thereafter.