Meesho — Exchange product not received and very bad customer service

I ordered the product from Meesho on October 22 and I received the product on 31st october. The size was not fitting, so I gave the exchange option. The delivery partner(from Ecom express) came and picked up the order on 1st novemeber. He had shown the picture of the product and confirmed with me and picked up and went. Later than evening, another person called me and asked that can he come and pickup the product. Then only I am realising the actual delivery partner is Delhivery. So they delayed the pickup, and I tried to contact the ecom guy, but I hadn't receiced any code, so I couldnt contact. But i got the order id, awb number and tracking link. After 2 days the Delhivery people cancelled the pickup thmeselves. Then it is shown in the aoo that the pickup is cancelled. Nothing is mentioned about the ecom. I contacted the customer care on 4th novemner and sent screenshots of thepickup confirmation message that I recieved and the tracking status screenshot. So then they said they will resolve the problem in 4-5 working days. I called them 3 times in 15 days and they told me to wait over and over. Then in the status it was shown that the product reached the seller on Nov 6. When I called the customer care on november 19, the customer care girl said that it had been solved and confirmed that I will revieve the refund in 4-5 days from so and so account(she even said the account name on call). Then on 20th, i received a mail from Meesho that it was found that the product is not picked up. Then I was furious and I called them for the 5th time, and then they said its a communication problem with the delibery partner, they are still resolving and i wasnt convinced and then they trasferred the call to a senior, and she said it will be processed and she will call me back in 2 days (that is on 24th Nov). It's 25th Nov evening today and i havent reveived any call or any mail yet. I am not understanding what is the probelm with their unferstanding. I had the confirmation SMS, I had the Air way bill no., I had the tracking status, and it is seen that the item is delivered. If it is so, if not the echange product, I am not understanding why they are not giving refund. First of all, who even assigned these Ecom people if not Meesho? How did they get the product details and photo. So if there is a communcation problem also there is no doubt that the product has reached back the seller. Full proof is with me. I want a resolution from Meesho and also a compensation for all the difficulties they have caused me. They not only just put me in a difficult sitiuation with money loss, but they didnt even keep their words. I have all the screenshots and call recordings for proof.