Returning a new in box item after the buyer opened it
I have a buyer requesting a refund on two barbie dolls that were sold NIB. However, the buyer opened both dolls and then attempted to reattach the dolls. They broke the package seals and even damaged one causing the cardboard to come apart and loosened some of the accessories inside the boxes. The girl doll was taken out and played with, I know because the dolls eyes are supposed to open and close with warm water. When I sold the doll they were closed and now they are opened which cannot happen unless someone applies water. The girl also comes with a Little Golden book which was attached securely in the package, now it is upside down on the opposite side, if you move the box you can see it is loose.
I cannot sell these items as NIB now. The buyer is requesting a refund so I do not know what to do, this is my first return in 3 years, any advice?
Thank you-Libby