Ebay doesnt protect sellers from obvious fraud

[brownboy3491]

sold a $300+ item that weighed 4 lbs , buyer said it didnt work, I know it worked..
agreed to let buyer return item for full refund
buyer sent me a 2 ounce package with completely worthless contents
Ebay looked at all the documentation I provided, including actual pictures of the 2 ounce envelope that would need magical powers to contain the 4 pound item I shipped  out
then ebay took the money from my bank account
I have 715 feedback over 20 years, the buyer had 1
why would I ever use this service again?

[mega-ma-roo]

It is unfortunate that in a buyer said/seller said situation eBay will always side with the buyer despite any evidence such as you provided. Have you tried appealing the decision? See here for details:

Appeal eBay’s decision about a return or missing item for sellers | eBay

You could consider filing a police report on the theft and using the police report as evidence in your appeal. 

As a final option, you could consider an arbitration or small claims court action.  See the legal disputes section of the eBay User Agreements for details:

User Agreement | eBay