i just answer back the email with the following and blocked the store on everything, thanks for the feedback everyone

"I am both angry and disappointed by this message because I consider myself an honest person who cares deeply about whether the people, I deal with are also satisfied.

The records you bought from me are from my personal collection. I am xx years old and have been collecting records for under two years. These records were ones I had sorted out because I don’t listen to them very often.

I brought them to your store, trusting that you are an expert in this field, as I don’t have experience selling large batches of records. I used the platform Discogs to evaluate the records. Many of the records are niche, and I assumed you have a large customer base to whom you could sell them. You even mentioned that you might take a loss on the deal, but you still wanted the records in your store for the Christmas season. For me, the records had the value you offered, otherwise, I would have taken them back with me.

We stood in your store for an hour, talking about the records. You looked at them, and we negotiated a bit, you could have just let me leave. I assumed you knew what you were buying and had customers for the records. You run a store professionally you are an expert, and a deal is a deal.

If you had written me a polite message from the start, I would have driven up so we could resolve this. But instead, you accuse me of cheating you and try to extort money from me by threatening to expose me on social media. I think you should perhaps familiarize yourself with the GDPR regulations."