Myntra.com — Wrong product sent and return request rejected

I had ordered two Marks and Spencer t-shirts and one Gap t-shirt on the 13th of August 2021, all were size XS for my daughters. I received both the M & S T-shirts on the 14th August itself
I got a myntra packet delivered at my society desk on the 21st August which i collected for my Gap order. To my utter disappointment the packet contained a Male U.S. Polo Assn Shirt instead. The tricky part is that the invoice in the package was of the GAP T-shirt and it had my name and delivery address accurately. I registered a complaint within 30 mins of the delivery. I was asked to file a return request and also mention the reason for return by the customer service correspondent .I wrote that the product delivered to me was different from the one I ordered. The next day a delivery boy from myntra came for pick up but he refused to take the product. I have been on this issue for 10 days now. My return request earlier was denied because the return guy said the product I'm returning and the product he is supposed to collect are different. I have spoken to the customer on 3 different days the dates being 21st August, 28th August and today being 30th August. The 1st and the 2nd correspondent told me that the wrong item will be collected on or before the 31st of August. I have tried in vain to explain the issue but they are refusing to believe me saying that I am lying and that they have delivered the product as mentioned in the invoice i.e. the gap t-shirt
The price tag on the polo shirt says it costs Rs.2299 but the gap t-shirt I ordered only costs 749, I tried convincing them that I am not lying .
Today I received a mail at 12 noon that my return request has been cancelled and another mail at 12:03 that" return rejected as it failed quality check". The mail says" the product you returned failed our quality check parameters, we will reship the products to you". The mail is absurd, as we have not returned any product simply because nobody has collected it and the question of failing quality check does not arise.
I got on call again with a customer care and they said they have investigated my registered complaint and their investigation states that the right product was delivered and that my issue will not be resolved. So basically, they make a mistake, I do not get what I want, I do not get a refund and now I have a product I do not want and do not what I should do about it.
The customer service has harassed me wasting my time, energy and efforts in trying to convince that about my grievance. I hope nobody has to suffer like I did hence I have decided to complain to you. The biggest breach a corporate can have is a breach of a consumer's faith and trust. I understand that this is 1 incident and not a norm but this 1 incident will always prevent me from trusting Myntra again and that's not because of the mistake but because of the way it was handled. Making a mistake is one thing and not rectifying it is another and saying that the consumer is lying is a whole league apart. I'd like to seek help from this forum to alleviate my grievance