Shopify complaint: Thieves

I placed an order with a company Praceore and they use shopify as payment. After a week, I asked about a tracking number because I had not received one and I made it clear I wanted my money back. Suddenly the next day I got one, but it was an incorrect one. The company refuse to refund my money and I was told it would arrive in 3 to 5 days, and it was US based. The order placed on 424 and I got it yesterday 0526 and sent it back. Now, suddenly the company says it can only give a partial refund because they attempted to deliver it several times, which is a lie, that was never mentioned. My address hasn’t change nor any corrections been made. I contacted shopify and their response was that they were a liason for the criminals. If that be so, why wouldn’t they contact them when I asked them to, to mediate, that is what a liason is. I filed 3 complaints with legal and no one has contacted me back and yet the criminal is progressing.