unauthorised debit

I app**** online randomly just to see if i qualify for a loan and they did not say anything about a service fee or any kind of fee and then just sent emails to say i bought some service package and still no fee mentioned or what amountand when its due or how its to be paid. As soon as they saw money enter the account they debited. I think this is ******** and seeing as i am not the first complaint about this, something should be done to this company. Does anyone know what can be done to stop this company from doing this again.