Is she get the money back via dispute case, resolution center or buyer protection program?
You should upload all your information there for PayPal review.
Post a tracking number for selected carrier operator. That tracking information should be visible and stated as delivered to you, that woman and PayPal resolution department.
Why it happenes so she get forcely refund back? Maybe you didn't participated in that dispute?
Read up on many factors all listed in Paypals seller protection policy for you to read so you can risk assess your transactions. Legal (bottom right of Paypals pages) > user agreement > seller protection.
If you have proof she received it but lost the dispute for whatever reason then you could try the small claims court?
Advice is voluntary. Kudos / Solution appreciated.
