Hi I have this on my statement, after selling items over a year ago and I haven't sold since. When I got my last statement which was today it reads -£9 no payment due. The £9 was a charge which I paid over a year ago. As far as I know its just a reminder to let me know and to keep records of my transactions. I am not sure if you are actually in credit? If your owed amount was £30 and you paid it twice there would be £60 on the statement. You need to recap and try to remember what you owed. How did you pay twice.