How long do you have to post an article back if it is not right?

[ed6262]

A person I sold to left nasty feedback over one mistake I made in the ad and has kept the article for over a month before posting it back. 

[repentatleisure1952]

The answer to your only  question is 180 days with PayPal.

Why not provide precise details of what is happening?

[imastawka]

Feedback states you sent the wrong item.

That's not a mistake in the listing.

Have they opened a case, or have you just agreed to a return?

[ed6262]

I agreed to a return a month ago. 

[digital*ghost]

It used to be 5 business days pre-covid-19, but eBay extended it to 21 business days. This is basically just over 4 weeks, which is just a tad overboard IMO (especially considering they're not giving sellers this same kind of grace when it comes to INR cases, but I digress...)

If you accepted the return a month ago, the time would either be getting very close to running out by now, or has already, so the case should time out and close in your favour if the return is not made by the buyer.