If I can give this company a zero I would!! They a...

If I can give this company a zero I would!! They are by far the worst company I ever had to deal with...ever!
I called in March 2020 to cancel my service as I was going with a different provider. I am not under contract with ADT by the way. I was told everything is canceled and I am good to go.
Then a week later my credit card gets billed again because they had my credit card on file. I call again and I ask why my services hasn't been canceled yet and they told me whoever did the cancelation did not process it correctly and they assured me that it was canceled. I ask them to send me an email to confirm the cancelation and they told me they don't do that and that I just need to take their word for it.
Then 2 months later I received an email (in my junk mail, I was lucky I saw it) that I owe them for 2 months service because my credit card wasn't going thru (they couldn't auto charge me cause I got a different credit card number). So I call Adt for the 3rd time and they said that whoever I spoke with before didn't complete the cancelation again!!!! I was furious...and again they said they will cancel but couldn't not provide me with a confirmation email!!!! I don't understand why this company just won't cancel my service...this is illegal!