I sometimes hear from students who are worried that their examiner seemed rude or angry in the speaking exam. Maybe the examiner didn't smile or make much eye contact, interrupted a lot, or kept looking at his/her watch. Does this mean that you will get a low score, or that you should complain?
The answer is no! Don't worry, and don't think that you need to complain. The examiner's attitude is not important at all, and you should ignore all of the things I mentioned above. Focus only on answering the examiner's questions as well as you can.
Remember: it's possible to have a very nice, smiling examiner who gives you a low score. On the other hand, an examiner who seems impolite or disinterested might give you a higher score than you expected!