@Veysel guessing you’re saying wrong amount. In any case, you may want to read through Saoiray's Discussion about Rewards payout amounts
It all depends on your country, ads available, etc. A lot of ads are about 0.005 BAT each. At least some of the 400+ ads you saw would have been House Ads, which pay nothing.
Let’s pretend you got paid all of them and they averaged about 0.005 BAT per ad multiplied by 400 = 2 BAT.
BAT is currently prices at $0.13480, which we can round down and say about $0.13 each.
So likely on the high end, you would have gotten $0.26
I’m in the United States where there tends to be more ads. I saw over 800 ads. Might actually have gotten to over 1,000 ads, but hadn’t paid much attention.
I received just over 3 BAT, for $0.51