If they popped it and the "it" that came out was one or two purple-reddish mushroom looking things, then chances are really good that you have a male. Females don't have hemipenes
If this was the person that originally sold you a "female," and have said it is now "your problem," I wouldn't put it past him to attempt to pop the snake again and purposefully NOT evert the hemipenes with you standing right in front of him. Just from reading your posts, I'm guessing that you are young and might have been seen as an easy target for a seller to pull one over on...
Follow the advice given to you, but understand you aren't the first to have this happen to them. Take your business elsewhere from now on and feel free to share with others whom you won't deal with anymore and why.
If it doesn't work out in your favor, chalk it up to experience, learn from it, and move on. If I dwelled on every mistake I had to learn the hard way, I'd be in pretty rough shape.