Bad communication and bad service with home choice

I opened a home choice account and selected the 3 months payment I was told by the consultant that I will be paying 650 a month agreed then I added more items and called how much will my balance be and I was told 870 for 3 months...I was okay with it...after paying for 3 months I was told my balance was actually 900 and something and I need to pay it back or else it will increase ,and the funny thing is that i did call home choice during my 3 months to ask how much is my balance but no response... bad communication I'm unhappy cos I'm sitting at home knowing I have paid everything