Must the questioner return the money to his friend who did not receive the product (international calls program) that he purchased to join the network marketing company, knowing that the questioner did not personally benefit from this amount and that the friend was aware from the beginning that the program had not been delivered?

The price of the aforementioned program is not guaranteed by you because you are an agent who paid it to the company, and an agent is trustworthy and only guarantees in cases of negligence. If you did what you were instructed to do without transgression or negligence, then there is no guarantee upon you. Subscribing to the company's marketing system in exchange for purchasing a product is impermissible.