Mistake #1: The phrase "Mistake in costumer service?" is not a question. In fact, it isn't even a proper sentence.

Mistake #2: The words "costumer" and "customer" are not the same. If you have dyslexia, please consult a reading specialist. If not, please see http://happyplace.com/9574/grammar-test-keeps-idiots-off-of-the-internet

Mistake Mistake Mistake Mistake was created in 2006.

The future tense of "mistake" is "will mistake."

Make a mistake is correct.

the mistake is []