How to cancel Umobile Postpaid?

Hi, I got called by U-mobile operator saying if I want an upgrade to free postpaid until august. Im too tired tht time and just say yes, "thinking oh new experiencee" I do bought some data and hospot booster. Today, Igot a bill state that my bill is RM101.67. I'm confused as hek. I check my activity and adding up how much do I bought the data and hospot booster and got around RM61.33 ! Where did tht RM40.28 come from?.😭 I miss prepaid :( and truly regret saying yes, I should just ghostting the operator until he give up tht day. I hate being nice. Now I have to pay tht shit. U-mobile is not even strong at my place anymore, I want my prepaid back.

Hi, I got called by U-mobile operator saying if I want an upgrade to free postpaid until august. Im too tired tht time and just say yes, "thinking oh new experiencee" I do bought some data and hospot booster. Today, Igot a bill state that my bill is RM101.67. I'm confused as hek. I check my activity and adding up how much do I bought the data and hospot booster and got around RM61.33 ! Where did tht RM40.28 come from?.😭 I miss prepaid :( and truly regret saying yes, I should just ghostting the operator until he give up tht day. I hate being nice. Now I have to pay tht shit. U-mobile is not even strong at my place anymore, I want my prepaid back.