guardian security services, inc tulsa continued to charge my bank after i dropped my service tulsa Oklahoma

AFTER THREE YEARS OF BEING A SATISFIED CUSTOMER, I CALLED THEIR OFFICE AND ATTEMPTED TO UPGRADE MY SERVICE. I WAS TOLD A SALES REP WOULD CALL ME BACK AS SOON AS POSSIBLE. (I WAITED TWO DAYS FOR THE RETURN PHONE CALL)(HOME PHONE HAS ANSWERING MACHINE, AND CELL PHONE DOES AS WELL.I ALSO HAVE AN EMAIL ADDRESS(EACH OF WHICH, I HAVE HAD THE SAME CONTACT NUMBERS FOR 10+ YEARS).
WHEN I RECEIVED NO CALL BACK, I AGAIN CALLED AND TOLD THE OPERATOR I NEVER GOT THE RETURN CALL, AND WAS TOLD HOW SORRY HE WAS, BUT HE WOULD BE SURE TO HAVE THIS MATTER ACTED UPON IMMEDIATELY. I AGAIN WAS TOLD I WOULD GET A RETURN CALL. AFTER NO CALL WAS RECEIVED, I CALLED ON THE THIRD DAY FOLLOWING, AND AFTER GOING THROUGH THE ENTIRE PHONE FIASCO HISTORY AGAIN, I WAS TOLD TO HOLD ON AND SOMEONE WOULD BE WITH ME VERY SOONAFTER ABOUT 5 MINUTES, THE PHONE WAS DISCONNECTED.
I WAITED FOR 5 DAYS AND AFTER NO ONE EVER RETURNED MY PHONE CALL, I CONTACTED ADT SECURITY. AFTER SPEAKING WITH THEIR REP, I SIGNED THEIR CONTRACT.
GUARDIAN SECURITY WAS CONTACTED, MY SERVICE STOPPED, AND I EXPLAINED THIS ENTIRE REASON FOR LEAVING, AND WAS TOLD HOW SORRY THEY WERE AND I WOULD NOT BE CHARGED FOR FURTHER SERVICE.
2 WEEKS LATER MY CREDIT CARD WAS CHARGED ANOTHER PAYMENT FOR THE NEXT MONTHS BILLING. AGAIN I CALLED AND WAS TOLD THIS CHARGE WAS CORRECT, EVEN THOUGH I HAD ALREADY BEEN TOLD BY GUARDIAN MY ACCOUNT WAS CLOSED AND I WOULD NOT BE CHARGED FURTHER.