I have received and continue to be sent Wu-Yi Green Tea and they have continued to charge me!!! I don't want this crap!!!

I ordered the sample of green tea from MBM&F - Wuyi but realizied that I was not able to drink the tea. I notififed them immediately to cancel any further shipments of this tea. I received another shipment in approximately one month and my debit card was debited for $69.00. How can I stop this fraud?
Please advise the procedure I should follow. Thank you.