Removing a listing after item is sold
I'm a novice at eBay selling. I sold an item on January 8th and shipped the same day, the buyer received and gave positive feedback. Unknowingly, 3 more buyers did a "Buy Now" on the same item within the next 3 weeks, but it was gone. Since I only had one item I was selling, I was not monitoring eBay, I did not know until now in September - 8 months later. They paid for it and when they didn't receive it, they filed a complaint, got their money back, and left negative reviews. I'd like to apologize to the buyers for their time and hopefully get them to change their negative reviews. I had no idea I had to remove a listing after I shipped it, I thought it was automatic when it sells and I am paid. Any advise besides go away you rookie! ?