Myntra - refund not processed after successful return

# ********************* "eCraftIndia Set of * Multicoloured Parrots Canvas Wall Art" .
I ordered a painting on myntra shopping app for Rs ****. it reached on *st august. i didnt like the quality of painting n I placed request for return. they accepted n asked me to selfship that which I sent to gurugram warehouse address provided by them by india post n tracking id confirmed delivery on ** th august. for * weeks they kept on asking us to wait....until when we strongly asked they replied the painting is lost in their warehouse n they need product pictures which we clicked to find that....they found that item on ** august n now same day they say that the painting failed quality check. after * days on asking again they told bill is not not box. we said bill is inside box. they said we didnt check inside. everyday * days they ask to wait another * business days. i thinkseller denied that product because of delay by myntra people in finding that despite us calling dem everyday n now they want to put blame on us.
i feel i m mentally harassed from a month. and from now on it will be hard for me trust any online shipping company. i feel i m cheated.