Very pathetic service!!!

I canceled and deactivated my Rain sim a month in advance, never used it and installed fiber. Now I get an SMS stating I'm in arrears... ******** man! I'm not paying for something I never used, canceled in advance and even got that "we're sorry to see you go" message. I paid my last debit which was last month and somehow Rain has re-activated my sim which I no longer have or use!!! If I get debited now, I swear I'm going very public with this pathetic service!!