13-10-2020 9:51 PM
Unfortunately your disagreement will count for nothing if she uses eBay's money back guarantee.
EBay's policy, which you accepted in the user agreement, is that when they can't determine that the item was as described, they will support the buyer. As eBay never even sees the item, before or after delivery, they have no idea whether it was as described. As a result, buyers can claim any fault to get a full refund. No evidence is required.
If the buyer returns a completely different phone, don't count on eBay taking your word for that either.
EBay is a very risky place to sell things. Every sale is a gamble whether the buyer will abuse eBay's money back guarantee.