Ah yes! You fell into the classic trap of YesBank sales agent. I had suffered the same with prosperity rewards plus card.
If you have any call recording/ WhatsApp chat proof of the agent saying you'll get LTF card, then call customer care and say you were told you would get a LTF card but now there are charges and ask them to make it LTF. If they don't budge(which they usually don't) ask them to raise a complaint of mis-selling and put a mail to grievance redressal/nodal officer as well.
The sales agent will then call you and beg you to take the complaint back. If you have the proofs as told earlier, send those to grievance mail or nodal officer. Let them decide what to do and even then if they don't make it LTF, after 30 days from the first mail raise a complaint in RBI Ombudsman portal regarding mis-selling.