Myntra.com — Not giving refund since around 3 Months

I had returned "shaftesbury navy blue blazer" with tags intact, since the quality of the product delivered to me was not good. The return was done in feb'20, however i have still not received the refund of rs 1799. They are continuously stating that "product quality failed". However this is their own mistake since i didnt use the product at all.
In summary, firstly they sent "inferior quality" product and upon returning myntra is not giving me my refund yet.