Advertising campain

I have set up an advertising campaign with 50$ + 50$ bonus from startapp.
I have run the campaign over the new years eve 31 and 1 ianuary

Today I was stunned to see that I am overbooked with a budget spend of 195 $ al thought i have set up the maximum budget of 100$. Good question would be how pay the difference ? and why the servers did not stopped the campaign once the budget was riched ?

Boom 40 000 clicks over the night ...I wonder how much represents installs ? any idea ?

What was your experience ...is this a good result ..I expected to see impresions over a week

Have never set up campaigns yet, but I don't understand one thing

If you set a max of 100$, how the hell can they charge for 195$?

smallprint???

Results after spending 200$ over new years eve
530 000 impresions
40 000 click
300 installs
100 new active users
2 / 5 star rating

I let you judge these it depends on what side you look at the campaign
my daily activity on 7 days
1260 visits
400 installs
40 new active users
1/ 5 star rating

So without spending any money in about 2 weeks I reach the results of paying 40 000 clicks over start app advertising campaign ...
and thinking that the 50$ added initially to this campaign was all my earnings on 360 days from my apps with start app