a bad audit

yesterday,i experienced a miserably customer audit. One side,the customer asked my a great deal of problems,some seem not very reasonable and maybe curious based on the point of audit,and attitude is not quiet kind. Needless to say,their intention is very suspicous. And in the break, sales told me that maybe they came to our factory just want to change the supplier. I am amazed seriously. (So, how i do it fully perfect and prepared adequately. It's no way to change anything. The problem is, if i know this deeply, that i will not be puzzled and beatened.)
The other side, my colleague didn't show totaly cooperation on this audit. When customer required to represent some explanations for some record. The guy left it and went to other site,even when he was told this. What a mess! So,i only can control my emotion and keep a smile to face with the customer's infinite pushment.
For me, i insisted that i can handle the audit and make customer satifactied,although i have knew their intention.So it's obvious i would definitely be defeated at last. It's surely a unchanged fact. My efforts proved to be useless. I cann't change the result.
Now,i am relexed from this because i have tried my best and understand this result cann't decided by myself.