That's very rude of them. Anyway, what was your exam location a school, prometric center or other institution. Sometimes prometric test centers are more strict.
My friend also experience that here in Canada. The ETS response is that "there is a feedback that they will be sending in your email and that's where you can give your feedback about the test center". I know that is just for research or some study but just send that report anyway.
Don't expect ETS to do something with your complain because they will just take it as a bad feedback to that test center.
Anyway, I hope you will still get the score you needed. Sometimes those who have bad experience in the exam are the people who have high scores. Just be positive and and continue to hope for the best.