Payment dispute has been filed for full amount but already given partial refund

[ravenddt140]

Buyer bought a set of dolls from me but on arrival some accessories were found to have come away from the backing cardboard so a partial refund was agreed. eBay then messages me a few days later to say the buyer was suspicious and had cancelled her bid and not to send the item but obviously this was too late.

A month later I get a return request even though shes now 'no longer a registered user' which I found odd in itself but accepted the return and the item was shown as being disptached a couple days later. Now all of a sudden I get messages from eBay that the return has been closed (so unable to track my return) as the buyer had filed a chargeback with her payment provider! Problem is the chargeback is for the full purchase price so eBay has said its witholding £135 and not the £100 thats left after the partial refund!

How do I proceed with this as I dont want to be paying back the full amount especially as I havent even got the dolls back and I only have 5 days to respond!!