Non delivery and No Refund of Goods from eBay since 2017

I have been complaining to eBay (***) since 2017 about 3 companies that failed to supply the goods despite paying upfront, eBay has not resolved this refund or assisted in getting the goods supp**** - Who can I pursue this complaint with. Are there any options available - I used my credit card to pay directly. eBay Customer Service - SR# ***