Honestly, we can not give customers any guarantee as business firstly depending on mutual trusts. : 

But time & experience will prove that we are serious and responsible manufacturer, and will always try our best to solve customers’ problems though sometimes it may not our job. (Everything regarding the production will be kept informed to you timely and ask for your approval if something will have be changed because of the reality.

All in all, everything is flexible, and you are dealing with true man not just the dead words!