Canara Bank — ecs mandate charge debited in account

I have a account in canara bank, garhwa jharkhand recently i have started a two sip in the month of october and i have been charged an amount of 354/- two times in the month of december for ecs mandate charges. The charges are high. And none of the branch executives are helping to resolve the issue. I wanna know that on what basis the bank is charging 354/- just for mandate charges. I cant just ignore paying 708/- in a month for mandate charges this is my hard earned money. Please give me a remedy to it.