State Bank Of India [SBI] — Amount debited 2 time wrongly

On 5th March I tried to withdraw Rs 20000 but amount did not dispensed and amount debited but credited after 1 minute. But again same amount debited as CSH WDL . Now I lodged the complaint with customer care and visited branch manager of SBI. But no satisfactory response provided by manager. After seeing lots of posts on the same issue, I am afraid wether the SBI will refund or not the amount. In case they did not do anything then I have to take legal action against them .