They continue to take money out of my account I have paid this company 900.00 for a 300.00 loahow do I STOP THIS .

This company has taken 8 payments of $120.00 from me over a five month period for a $400.00 loan they continue to attach my bank account on a bi-weekly basis. loan sharks don't charge this high of an interest rate. I have paid back $960.00 for a $400.00 loan that is more than double. I don't know how to make them stop!