Me too, I went all in on Apple stock when the iPhone was announced, on margin I was so convinced. Sounds great right? Well broker sold everything during the 2008 meltdown and lost everything.
If that is indeed what happened then that's on you for buying on margin (which is inherently riskier), and no fault of the broker. If that's not what happened, and the broker executed trades without instructions from you, I hope you got them fired at minimum.
Tangentially related: Martingale betting system (https://en.wikipedia.org/wiki/Martingale_(betting_system)). Aside from its theoretical impossibility, this system typically fails in practice when the gambler hits a house limit and can no longer continue placing bets.