Myntra.com — I am complaining about my cancelled orders

Website:

Myntra

From the past month onwards Myntra has been cancelling my orders and there has been no specific reason for that. The products are not even sold out but within a couple of days of ordering the orders are cancelled from the company saying " not able to deliver".
Now the problem is how do I use the Myntra credit amount if my orders are cancelled without my knowledge. No matter what I order it will be cancelled after 2-3 days. Even I have an exchange order pending which is still showing as delayed order on my Myntra app. I want Myntra to return my credit amount which will get expired eventually if not used within a year.
The customer care people doesn't give you an explanation nor they can tell where the product is lying in transit.
They will keep on saying sorry everytime I call to ask about the status of my products.