returns - How long do I have to wait

[snowbunnies2016]

How long do I have to wait receive a returned item. I have agreed to the return, (buyer claims there are 2 loose threads in the hem). I would have refunded in full and said keep the item, however, she was so rude in her email that I decided not to go that option. I have posted a return paid postage label with tracking twice, she said she didn't get the first one, (tracking shows nothing). Return Claim opened on 17th April and Return accepted by me on 26th April.SHipping label was sent on 22nd April so it's been over 4 weeks and she still hasn't returned the item and am not receiving any responses from her.

How long does the buyer have to return the item. I thought I read it had to be returned within 7 days from the time of agreement to return. Surely there has to be some point where the case can be closed.