Error 500-find an event due to IP blacklisting?

Hey

I'm using the graph API many different kind of requests.

I do sometimes thousands of call graph API within a day.

Now for one type of the request appears to be blacklisted on my server.

The request is/search? Q = term & type = event. I test it on another server, is also working with requests at the same exact! (A term that, in the same token ...)

My question is, would someone hearing the reading limit not to be overridden within a day?
If yes why graph API does not send an appropriate error status code instead of 500?