ecigsbrand.com took 73.98 after offering free trial will not let me cancel orders Internet

I applied for trial ecig to help stop smoking.This was advertised as free. when the item was received it seems that every 30 days I will be sent replacement cartridges & would be charged for them.There was no price included so do not know how much would be taken from my account.73.98 was the cost of this.
I have tried to cancel this order twice with no success.I have also requested invoices for the amount they have taken from me.I have not received the invoices & have been informed that I cannot cancel this order in an e-mail.
I will not phone USA to cancel this as I set this up on line I should be able to cancel on line.
This is a scam by this ecigsbrand company.
I have instructed my bank not to make any more payments to this rip off company. I would like my money back as I tried to cancel within the allotted time twice but they still sent replacement cartridges.73.98 is a lot of money o lose for unwanted goods I am a disabled lady on limited benefits & this rip off company took a whole weeks benefit off me leaving me with no money.