Item sent via ebay's international shipping program stuck in Customs
Like the title says, I sold an item to an international customer using ebays global shipping program and it's now stuck in customs. The item has been stuck in Mexico customs for a week now and the customer is furious. I tried reaching out to the courier eBay used (DHL) as well as Mexican customs and neither could give me an answer as to why it was stuck in customs other than to expect it to take a month until its released. I spoke with eBay support, and they told me the fault was not mine. They said if the buyer chooses to open a claim, eBay will cover the cost of the refund since the issue was on the fault of their international shipping program. I have communicated to the buyer what both DHL and Mexico Customs has told me as well as to open a claim with eBay, but now the buyer is going off on me in the messages, saying they will wait until the item arrives, give me negative feedback for causing the long wait time, then return the item for a refund. So my questions are:
1) can I fight the negative feedback? This just seems intentional to punish me despite me assisting them to the best of my ability, that the fault is on eBay's ISP and not me, and that I told him to file a claim to get a refund ASAP but they want to wait an entire month just to harm my rating.
2) if the buyer returns the item once it arrives, will I then be charged for the full amount since it's being returned to me and they arent opening the case or will eBay still cover it?