Seeking advice : commission on selling price + VAT

Hi. I am just wondering if i can get some advice on this issue which is on the back of my mind for quite long now. As you know all online selling companies (be it Food Ordering Platforms (FOPs) or ecommerce majors) charge a certain percentage from the seller on selling price. Now in some (i guess in most) cases the commission is being charged on selling price + VAT. For example if an item’s selling price is rs. 100/- and VAT (say 10%) is 10/- so the commission would be charged on 110/- instead of only on rs. 100/-. Apart from this commission, seller is liable to pay the entire VAT as well. So these companies are eraning from a source which is not someone’s personal income and actually is govt’s money.

As I said, most companies are following this practice however I dont agree with this and think they are taking advantage of some loop here (i guess our law is quite on this issue).

What do you people think? All major companies are doing so, so it’s fine? Is there any law which allows them to do so? Is it illegal as I am taking it? What does our law say about it?

Please share your thoughts.