Best Way to Deal with a Scamming Buyer?

Hey folks,

Appreciate any help and insight that you can provide. I sold a box to a buyer, who left a negative review and is demanding a refund because they say I "sent them a block of wood".

Obviously, I did not such thing. I videotaped the packaging of the product and sent it to TCGPlayer while elevating the case to support.

Is there anything else I should do now? Anything I should do in the future to protect myself from this happening again?