I've reported so many too
remember that hundreds of peoples reported that bugs too
they know about them, but they can't ansewer to all of reporters... (if they could, then probably everybody from dev team would do nothing else than answering emails...)
So in conclusion. They need time to find a bug, isolate it and then fix it.
Belive me, or not, but this game is for sure thousands of hundreds lines of code... Do you think it's easy to find one small line where is a small bug that makes game unstable? Sometimes it takes one week or more...