A few things to keep in mind.

It is very important before starting any kind of manufacturing process, making an order or anything to ask for a tech pack. This will ensure that the manufactured goods reflect what you were expecting and ordered. If not, it will make it easier on the manufacturer as they can simply send back the tech pack/technical specifications and you can give your feedback with corrections if needed. This will save both time and money as there is no need to re-manufacture things that are wrong or bend rules; once is enough!

Don't worry though; if this hasn't happened and there is something wrong, don't panic! As long as you have given your manufacturers everything they need: correct measurements , materials , designs etc., then chances are you'll receive the samples that you've ordered.