Positec Tool Corp After 4 attempts to return item I've gotten no response Charlotte North Carolina

I recently purchased a Worx leaf blower bag from Positec Tool Corp online, afterwards I was able to get through to the actual manufacturer (Worx) customer service who informed me I purchased the wrong item for my model number.

I attempted two emails and two phone calls with zero response.  At this point I'm approximately 3 weeks into this attempted return and still no response from their customer service. I have to now assume I will not be getting my money back and will have to keep a part that is worthless to me.

Their site asked me if I wanted to use my Amazon account and auto filled my info when I checked the box, and the sale did show up as an Amazon "Point Of Service" sale on my bank statement but when I checked Amazon it didn't show up in my orders, so I have no way of returning the item. From now on I will only go through Amazon directly, not some unknown site using "Point Of Service".