After 11 months, I am still following with RAIN to close my account

I used Rain for 1 month in April 2022. I cancelled the rain account at the end of April 2022, as I could not get good reception. The device was collected, and no data was used in May 2022.

From June 2022, I started following up on this, however no one has properly assisted, and thus I am still receiving sms from RAIN, saying that I owe money. Call no.’s – ***, ***, ***

The different departments don't to talk to each other. I was informed by the financial team to send an email on this dispute to -'***' on the 13 Feb 2023, and still no response.