Leroy Merlin and Marketplace ****!!

I made a purchase on the website for a Gardena 18V 2.5AH battery charger. However, when the order was delivered, I found out that it was not the item I intended to purchase. I went to Leroy Merlin Little Falls to return the item, but they advised me that it was a Marketplace item and needed to be returned through the Marketplace. The problem is, there is nowhere on the website to log or initiate a return, which is ridiculous.

Although there is an email address linked to the Marketplace, the responses from this email have been useless. They are unresponsive, and the few times they do respond, they do not provide any valuable information. I have been waiting for over a week to hear when the order can be collected and my money refunded. I even offered to take the product to them, but no one responds. I spoke to someone named Kieran at the beginning, but they have stopped responding.

Leroy Merlin has also been useless. When I send my query, they send the same query to the Marketplace and copy me on the email. This is ridiculous, to say the least. What is the consumer's recourse in this situation?