Reersal of R1500 debited

Finwell Last week saturday debited R1500 in ny Account which i din,t know they were going to debit,i don,t know why 1500 since last month they debited 658,00 which i never get any help,what they did it was so painfull since i don,t get paid that much,1500 is a lot to me,now i am so stranded since i am out of budget,please reverse my money i work hard for and cancel that debit order sine the is no contract signed..i am so hurt.