"when I got home in the evening I seen the option worth less than $400."
The bid may have been $500 when your broker bought for you. The $400 that evening could have been the CLOSE price.
If you were looking at live feed data you would see the price go up and down all day. Look at a 5 minute chart and you'll get my point.
If the price that evening was $800 would you think you got ripped-off? This is just the way it goes. Learn to trade without live brokers.
Go electronic, use Lee's broker, they are a good one.
Keep at it . It's not easy but it's worth the effort.