Rain bad service.

On the 15th of April 2024 I called rain to ask them to change the day of my payment and make it month end instead of the 15,the guy that was helping me said he did it... Come may I called again because it had required me to pay on the 15th again and it was a lady this time that said she is helping me fix it and that I should pay half price on the 15th I will pay full month end and I did that... Now it's happening again, month end of May I didn't get a message of deduction, meaning it's gonna be the 15th again of this month.... I'm just tired of calling rain non stop for help but they are failing me as their customer.... I kindly need help urgently!!!!!!