OOMA Charged me after I emailed them and called them to cancel service. Internet

I canceled my service last month and sent the device back to them two weeks ago and yet the continue to take money out of my account. I called my bank to have the charge reversed and the bank called them to dispute the charge. They outright lied and told my bank I called them on a certain date which I didn't and said I emailed them on a certain date also. Very deceitful and dishonest I will never do business with them again. And would advise that who ever reads this steer clear of OOMA.