Mirraw Online Services — I have not received the product yet and I dont want this product anymore as there is a delay so want a refund

Order number-M[protected].
I have ordered a jewellery set worth Rs 749 on 4th of August.Today is 23rd of August and i have yet not received this product.I called the customer care.They told me that there is an option of Returning of product but I can't see that option as when i am clicking on return its giving a message as return validity expired.I have not received my product so how can i click on that option of Return.I called them several times and they assured me that they will cancel my order and will refund the same but yet they have not done anything.Worse experience with this Mirraw.
I want my refund payment as soon as possible because its a delay and i dont want this product anymore.They assured that the order will be delivered within 7 working days.Its been 20 days more and i have not received my product.Very bad and worse service you have Mirraw.