Amershop.net wihdrew $4.94 from my checking account without authorization,causing my account to overdraft.I have never heard of this company or done business with any company even sounding like amershop.net. I now Internet

Amershop.net withdrew $4.94 from my checking account without prior authorization.  I never purchased anything nor did I recieve any services. I never even heard of this company or any company sounding like amershop.net.                                                                                                                                                                                                                                                           I now owe a $25 overdraft charge plus out of the $4.94. I am on a fixed budget and can't afford any unexpected expesses.                                                                                                                                                                                                                
I am afraid they are going to keep doing this until I pay $10 to have my bank information changed.