When you have an E-commerce inventory based business, you are going to have customer issues. That itself is undisputed fact, the sooner you realize it the better. Items or parts will be broken or missing. The shipper is going to damage something. Or the customer is not going to like something and they are going to tell you that its all your fault. When I first started selling in E-commerce; this use to really bother me a lot. After doing some research I found out that it is a normal part of business. You simply cannot make everyone happy all of the time. So how do you deal with it? Actually you deal with it one customer at a time but you have to have a system.
Thinking through potential problems is a great way to start. You have to actually plot it out on paper the things that could go wrong or get broken and write in a solution to fix it. This for-thought will keep you from having the fireman principle. That is, you spend a lot of your time putting out fires and stressing over them. You do not want to get into that mode of operation. Probably the biggest factor is a dent in your encouragement. Realizing that these things do happen; make a big difference....