Your son is entitled to a copy of his training record - might make interesting reading!
...and...
Its better to draw attention to the fact that they are probably not following their training operations manual / basis for their ATO approval. If they are not doing one thing then they are probably not doing others.
As has already been stated, each course must be approved and each lesson laid out in the training manual. You should be able to see a copy of this and this states what should be being taught on each lesson. Where there is / are issues with a students progress these should be clearly documented and the student should sign record after every flight - (not necessarily to say that they agree with the comments, but to acknowledge what has been written)