I sold a fountain pen to a buyer who received it a few days ago. On the date of tracked delivery they contacted me to say that the lid would not stay on & they would like a refund. Then again saying that the clip would not work, then again saying that they could not get it to write. 

I initiated a refund but I think I've been had.

With that in mind, can I still send the buyer a return postage label so that I can see if anything was actually wrong with it?

Caroline