Wrong items delivered, how long before I can dispose of them

[Chersfrozenface]

An online retailer sent me someone else's order. I eventually got the items I had actually ordered. But despite me asking repeatedly for the QR code I need to return the unwanted items, I've received nothing.

How long do I have to keep them before donating or recycling them?

And presumably I would have to contact the retailer once more to give them a deadline.

(They're about 4 sizes too small for me and definitely not my style.)

Keep them for 6 weeks, so 30 business days, and make sure you have proof that you sent the retailer two emails asking them how you can return them.

It actually costs the retailer a lot for you to return goods.

Thank you.

Unfortunately there's no attended mailbox. I've had to communicate through Facebook Messenger. I can always send screenshots, though.