Unauthorised billing

Started with Rain in March this year and canceled them in April. They did not pick up their device so i had to call them to pick it up and turned out that the service was not canceled, had to cancel it again, 3x more time to when they finally said it wss cance and someone will pick up the device. Nobody came and i was not going to call them ever time to remind them. Then 6 months later in April, they all of a sudden deducted 2x payments on the same day without my permission. Have been trying ro get my money back for a couple of weeks now but they do not get back to me. Even after they acknowledged that the service was canceled in April.