Snehanjali Electronics — wrong amount charged as per communication

Address:

Thane, Maharashtra, 401303

I had purchased the cooler from the store, and as per deal it should be on emi. Staff shows the breakup and we were agreed to pay rs.745/- p. M. And total bill was 8300/-. But snehanjali staff deducted the full amount of 8300 without informing me. And i had consider i have purchased a product on emi. Every month rs.400-420 was deducted from my bank account. When i asked to bank about amount then they told that no emi running on your card and this amount is deducted as penalty because you have not paid outstanding 8300/- + charges. So same thing i have told to snehanjali manager and operations manager but they told that we dont care and we got our amount so we cant do anything. So the product of rs.8300/- and i have to pay around rs.122244/-

Is this fair???

Please help me in this.