Mismanagement

I requested a quote on 10 July for 5 books from TakeAlot the quote is valid till 24 July 2015, and yesterday when I made the payment based on the still valid quote I discovered that I'd been over charged for a book by TakeAlot. I had been credited for one book they no longer had in stock but its an under credit as far as I'm concerned. I have been trying to follow up since yesterday about this credit amount and the my money getting paid back but to no avail. Then this Brumilda Marcus person just sends me a standard cut and paste answer that prices are subject to change. This is not acceptable and no where on my quote was there any mention made of prices being subject to change, what is mentioned is that my quote is valid for 14days and i am still within those 14days. Can someone at TakeAlot please help I want my full amount back for the outstanding book please, I am not happy with the way things is being handled right now.