Dooostore Charged my credit card $97 then emailed saying they did not have item and would refund $$; have not refunded $$ California

I ordered a lawnmower from Dooostore May 15; they charged my credit card and I got an email confirming the order.  Five days later I got another email informing me that they didn't have the item in stock and would refund my money but it would  take six to 20 days. 

Eight days later they have not refunded the $$ and credit union says it's a scam company (as do others who tried to order something from them).  There is no phone number of physical address on their emails and the email has many spelling and grammar errors suggesting that they are not fluent in English.  Their website appears to have vanished as well.