They have probably only frozen the funds from this transaction, which is SOP.

Unless the Op has had multiple claims of not as described.

OP - Paypal do not generally look at indivual sellers, and certainly not their feedback, or their protestatiopns of honesty.. They are a business and you need to treat with them in a business-like manner.

If the buyer doesn't return the item (at their expense by trackable means) the case will time out and your funds will be released. If the buyer does return the item and it is not in the same condition as sent, then you need to prove that to Paypal, who will then release your funds.

If it is in the same condition, then the buyer has decided they paid too much. Depending on the buyer's level of experience, they might not even realise they will be out of pocket for the return.

Either way, I would be putting them on my BBL.