Pathetic service!

Pathetic service! I called to cancel my sim on the 19th of Feb. They told me it will be deactivated on the 28th of Feb 2021 and last payment on the 1st of March 2021. I check to see if it is cancelled and now it says it will be cancelled at the end of March and last payment 1st of April 2021. I called to find out what is happening and nobody can help and all they tell me is that someone will call me and I’m still waiting! I refuse to pay another cent towards this terrible internet provider!