Fraudulent buissness pretending to be me

So this morning I was checking through a few listings and seen that there was another seller called “UK fixings direct” selling on my listings my company is called fixings direct I have a trademark etc. I believe it could be someone who knows me or knows of my business as soon as I told people about it & word got out the listings were deleted within around a hour of doing so they are trying to defraud me what can I do about this as I contacted seller support and didn’t have much luck.