Amount 7000 withdrawn without my knowledge

Date 30.03.2018 my SBI account has accessed by some one without my knowledge, they withdrawn 30,50,250,500 rupees of indian money with total transactions of 63 from same POS 248742000103177. I want my money refund, what is the procedure for this. I raised a complaint in customer care and also in SBI homebranch but there is no response from SBI. Totally frustrated with the service and response from the team.