You are paying these commissions to the banks/brokers/agents that your are transacting with. They usually are not direct with you and give the following reasons.
1. They claim that they are not charging you anything. It is a free account.
2. They claim that the commissions are paid by the fund houses and not you the users.
Both are white lies. These commissions go to them from your returns and are considered into when NAV is calculated. Hence notice how the NAV of all the regular plans will always be lower than Direct plans. This difference is because of commissions and reduce your returns. Because they make hefty returns through commissions on your investments they offer transactions for free and claim that it is a free account.
Choose Direct plans to stop losing your money in commissions.