I wanted to pay my internet bill is there any option to pay online. I hardly have any idea about internet and online transactions but I need to use this facility so some please help me for providing?

There is a place where you can pay your internet bills online, you just have to pay the amount along with your bill details they will pay that online.

They will do it by using their credit card and they will take extra money from me right?

Yes they will take the money from you but they will not take extra money from you and yes they will use their credit card for the payment.

Will they provide me with the true copy of the bill to make me sure that the payment has been done.

Yes they will do that they will make the payment and a true copy of the receipt will be given.