PAY JUST NOW with zero customer service

I bought a ring from a mercahnt SHINY ROCK POLISHED using my pay just now,i made the first payment on the 25th of november,SHINY ROCK POLISHED could not delivered when they were supposed to deliver and said i would get a refund,its the 27th of december now,more them 2 weeks since my refund was promised,when u use the PAY JUST NOW APP u dont get any service..ive sent emails with zero reply...luckily the account i use to make payments is a separate account so i dont leave money in it,so the second payment was suppose to go of for an item i havent received and u cant contact them because they dont respond to your emails