Unlike physical products purchased at a store a digital product once purchased can not be effectivly returned. When you buy a physical product at a local market, if you are unhappy with it, provided it is not materially defective, you return it, the store refunds your money and the item then goes back on the stores shelf. In effect the sale is simply canceled with everyone returning to a pre sale state. The store has the item for sale on their shelf and you have your money back. It is as if the sale never even happened.
However a digital product often can not be returned. If you buy a software or a training for example you can not generally give it back once you download it. Because of this both the buyer and the vendor can not be returned to a pre sale state. You can get your money back, but you will still have the digital product you downloaded but can not return.
Due to the nature of you not being able to return the training after you have purchased I have a NO REFUND PERIOD POLICY.