Hi Guys,
Sorry for the delay. If i can find any easy way for my customers to buy bitcoins using their cards then I will consider using bitcoin gateway. BTW I would like to thank you all for your suggestions.
If you can convince your customers to pay the fees, here is a list of services which accept credit card payments for bitcoins:
https://www.simplex.com/bitcoin-partners/Simplex is their common payment processor. When buying bitcoins from any of the services listed on the link above, the transaction is processed by Simplex.
For information about the procedure itself, here is Simplex's FAQ's page:
https://www.simplex.com/faq/The daily and monthly transaction limits are fairly high which should suit the needs of a medium to high tier business accepting credit card payments. Simplex verifies buyers very thoroughly. Your customers should expect to be KYC verified during the buying process. I don't think they can easily chargeback money from Simplex. This is a company which fights chargebacks tooth and nail.
One of their listed partners hosting the Simplex card payment service:
https://bitcoinbycredit.com/