Ixigo — IXIGO is not issuing full refund as mentioned/promised in the flight ticket

I booked an international flight on 15th dec'2023 from new delhi to catania, flight date is 11th jan 2024. I choose the ixigo assured program while booking. I received the email with the flight details mentioned. On the top of the flight details pdf, it is clearly mentioned that you will get full refund on cancelation. But today, now around 2.30pm when i am canceling the flight ticket, ixigo app is showing refund. When i booked the flight they showed me that you will get refund of flight ticket but not ixigo assured amount which was around rs4000. I contacted customer care, now they are telling me that you can only cancel before 72hrs. But it is not mentioned on the ticket they send. This is absolutely ridiculous, they mean i lost my money because of there fault. If it is mentioned on the ticket, i would have canceled yesterday. Could you please help me in getting the refund? I would have to book again for next month.