Guild Wars 2

I bought 6 superior runes of Lyssa, put one on my armor and had 4 left. I double clicked on the warning, maybe that’s where it went wrong.
I checked my inventory and my TP history and it says i bought 6, I’m a little upset about this.

I have had this happen before, thank god it wasn’t with superior runes (some are very expensive). Is there a chance that you put the second one on the same piece of armor that you had already put one on?