FNB Rob's customers by putting monies in pending yet make it accessible!!!

I purchased something in November for R1441 and the amount was only seating in 'pending' till now the 6th of January but the transaction has now left my account in -R1441, so meaning that I'll be paying that 1441 twice because the transaction I made on the 21st November was already taken away from my balance and now my account also shows a negative of that very same amount which I do not accept! If that amount was not paid then where did it go to because it left my account and sat in silly pending whatever! Can FNB please reverse the negetive amount because I will not allow them to rob me just like that!!! They need to stop this nonsense of making pending amounts accessible because once we transact and money leaves my account I will always be under the impression that I've paid my dues and the money can never be accisible for me to use!