Shark Offers - Product not delivered, and the seller is not responding

I have placed an order in the Shark Offers website on May **th, and so far I have not received the items.
My order number is #****, and it was for $**.** USD.

I can see the details of my purchase online, but I have no information on the delivery, nor are they answering my messages.
https://checkout.shopify.com/********/orders/*c****a*******c*****a**ff**c*f*d

They provide an email for contact (sharkoffers@hotmail.com), the one time they answered me, was to say that the order was coming, but so far, nothing.

I would like to the product to be delivered, but since it has bee so long, I would be happy with a refund.

I don't know what else I can do to have this resolved.
Could you help?

Here follows the information I I can find about the company on their website (https://sharkoffers.com/):
Company Registered Name: Rocket Ecommerce LTD
Company Registered Address:
**-** Shelton Street
Covent Garden
London
WC*H *JQ
Company Registered Number: ********
Place of Registration: London

Att,
Mariana Carvalho