MARK WHITEHOUSE says:

When buying any trained gun dog, always do your homework and make sure the trainer is a reputable one with a good, proven track record.

Always take time to write down a full list of commands from the trainer that the dog is used to and, when watching the demonstration, always watch both handler and dog, don’t just focus on the dog.

We all use different body language and have different tones of voice so it is very important at this early stage you get it right.

Take time out and book a few training lessons with the trainer you bought the dogs from and let him show you where you are going wrong.

I suggest both you and your son have a joint lesson because I presume both dogs are experiencing the same problems if bought from the same trainer. Most trainers usually give a very good after sales service and would not normally charge you for the first few training lessons.