Air India — Refund not provided

I had purchased 4 tickets from Singapore to New Delhi on 12 December 2020 returning on 20 December 2020. The flight was cancelled due to Corona virus and I claimed for refund in October 2020.It has been more than a year now and every time I have called they have acknowledged the claim and said they are processing. To my surprise today I received an email stating that refund was made in January 2021. When I have received no such refund from Air India. My e-ticket numbers are E-TICKET NUMBER:[protected], E-TICKET NUMBER:[protected], E-TICKET NUMBER:[protected], E-TICKET NUMBER:[protected].
Please provide refund for my tickets at the earliest.