CJ Environmental Cash for Diamonds USA listed company failed to provide adequate funds for wedding rings sent to them Foxboro Massachusetts

I found this website online and they appeared to be legitimate and credible. After I contacted them originally, they sent me a secure mailing envelope for my merchandise. I sent a wedding ring and an engagement ring that had diamonds and white gold and had been originally purchased for over $5,000.00.

They sent me a check for only $40.86! On their website they state that within 14 days of the date printed on of the check (10/24/2019), that if they are notified, the check can be returned and they will send back the merchandise.  

Now when I try and contact them they do not answer calls or e-mails.  Now it has already been 8 days since the printed check date and I am unable to contact this company to notify them that I am not satisfied with their payment and would like my rings back.