Beware of TheclubJersey

I purchased a Manchester United kit some time ago, but it has yet to be delivered. When I check the website, there is no record of my order in the order history, nor does it show any completed transactions. The email address provided by the seller is invalid, and the listed phone number is either continuously ringing or switched off.

I initially discovered this seller through a post on Reddit, but I now suspect the post may have been created by them to boost sales.

What would you recommend I do in this situation?