Jet Airways — charged us way higher saying it's a low cost ticket

Address:

Mumbai City, Maharashtra, 400067

I would like to bring to your notice that we had booked a ticket on 17th october for 7 adults and 1 infant, it showed it's a low cost fare and charged us rs46886, today 20th october for same 7 adults and 1 infant its charging rs 35578, we are looted with giving an explanation that due to low availability than it was charged higher and now due to high availability it's charging lower, the difference is more than rs.1500 per ticket... We seek for refund for higher charges and misguiding the passengers.