Flipkart — Cancellation of exchanged order by Flipkart without my consent after the return period is over

Address:

Vaishnavi Summit, Ground Floor, 7th Main, 80 Feet Road, 3rd Block, Koramangala Industrial Layout Bangalore Bangalore District Karnataka India 560034

Hello there. I was using Flipkart for about more than 3 years until they recently tricked me. I placed an Asics sports shoe bearing Order ID: OD[protected] on 07th April 2023 and I received the order on 10th April. The size of the shoe was too large for me and there were no smaller size available of the same colour. So I decided to wait for a smaller size to get back in stock as I can exchange within 10 days according to Flipkart policy. But unfortunately no size came back to stock. So on 15th April 2023, before the expiration of my return policy I placed an exchange request of a different colour (smaller size) bearing Order ID: OD[protected].
On 21st April 2023, I got an SMS in the evening that my exchange order is out for delivery but it didn't reach me. I thought that due to some circumstances the order may have been rescheduled. No courier agent tried to reach me. On 24th April 2023, I got an email that my exchange order was cancelled. What! Then I tried contacting the Flipkart customer care and they told me that the cancellation was not done from their end. I want to ask Flipkart why would I cancel the exchange order knowing that my return period is over?
Now I can't return it nor wear the oversized shoe.
Please help.