Unhappy client

I requested a cancellation from Rain in April, and a consultant called me after a week and informed me that the policy would be cancelled To my surprise end of the month, they billed me for the month of May sent another request to cancel they called and said cancelation was processed asked about the balance informed them that the sim card was closed and yet im being billed for the month of may she said she will get back to me till today still waiting and they billed me again now up to 1600 in balance for a closed sim card not why they keep billing me. ive trid everything to communicate with them and asked them to clear the balance and cancel this SIM card. to them, even though they closed the SIM card, i still need to pay for the subscription, even though asked a couple of times to cancel.