I'm trying to cancel my service but they kept char...

I'm trying to cancel my service but they kept charging me and don't refund my money. I called and they said there is a cancel fee unless I cancel when it's near the month end of contract. I called in April. Now June 01 and I got a pending charge on my credit card. I called and they said "I see you have cancelled on April 09 but I'm not sure why you are charged, I'll email my manager to refund but not sure when will hear back.". Today I get charged. I called again and I got cut off. DO NOT GO FOR ADT