Bank Of India — Regarding rude response from BOI,Mangle

I am having loan account in BOI, Mangle branch. There is issue with amount withdrawn from my savings account and transferred to loan account. My first installment is of 6539/- but amount withdrawn is 13125/- so for that I called Bank but no one responding and there was issue with there phone. So I called around 7-8 times but they pickup call and then directly cut the call without any notification. I asked them to give me anyone's personal number I'll call on that number but they just told me come to branch and cut the call. I am out of station and far away from branch so how should I visit bank branch? This is not a good behaviour by any bank. Don't understand how they can do with their customers.