namecheap.com domainscheap.com stolen 3 domains names and sold them even they were renewed!! Internet

I renewed my domain names evermd .com, everflowers.com evereducation.com on October 28th, 2017 with domainscheap.com. Payment was accepted and I received email with receipts. I owned these domains since 2000. I presumed that all is good till today when I discovered that all 3 domains are gone from my account on namecheap.com. After a quick search online I found out that one of them evereducation.com is listed for sale on hugedomains.com for around $3000. I filed a complaint on cheapdomain.com online. Their mobile website is so bad that you can't see what you typing by the way and there is no phone number or address listed to contact them. They responded with the offer that they will go "middle way" and refund me a fees of $ 17.00. I responded that is they have to be kidding and that I want my domains back. They are the worst scammers, con artists and thieves. They stolen my domains and sold them on auction, even they were renewed on time. We filed a complaint with Icann and waiting for their response. Also if domains are not returned we will file a lawsuit. Any suggestions how to deal with the theft like that very welcomed. Please do not become another victim of namecheap.com