Upvote:6
I wanted to help them but I have no idea how to help them
Find out the reasons for the refusals. They will very likely have been given specific reasons. If they have the refusal on paper you can publish it in a question on this website after redacting (blacking out) the personal information.
Encourage them not to try randomly choosing types of visa in the hope they'll get lucky. To the officials that just looks like deliberate deception. It is the sort of behaviour that can lead to very detrimental consequences.