[Kikibosum]

do you have an idea of a pretext in case they ask me to send the pair back? It would be impossible since I have had them on my feet for 2 weeks.

They refused your return which Is absolutely no fault of your own, so you decided to wear them.

They're at fault for noncompliance.

And, when making a claim from Paypal with the above mentioned arguments, how does it work? I have never done this before.

In your PayPal account, go to the PayPal Resolution Centre and follow the onscreen prompts.

Thanks.
When I access the center, different options are displayed and I hesitate between one of them:

Problem with your purchase :
-I would like a refund for all or part of the items in this order.

Problem with the seller:
-The seller did not respond when I contacted them regarding a problem.
-I am not satisfied with the seller's offer.

I think the most appropriate option would be the problem with the purchase I am wrong?

Edit : I clicked on the first option (I want to be reimbursed for all or part of the items), but it asks me to choose an option that best fits between those:
-I did not receive the item
-I received a different item or one that does not match the description
-I received the object late
-I cancelled the item
-I have already sent the item back

Only, none of these options is convenient for me. What should I select/do?