Reputable suppliers handle customer communications efficiently and can easily be contacted directly either by email or telephone. They also handle customer problems swiftly and compensate adequately. Look for feedback from existing customers where they have contacted the supplier and they have been taken seriously and their matter has been handled professionally.
Another good way to test the customer service is to contact the manufacturer and ask sample photos taken on trail camera model you are planning to buy. If they reply you and deliver samples, or point you to sample photos on their website, then there is a reason to believe that they value their current and future customers and will also deal with your problem if you happen to encounter any with their product.