Unrealistic premiums

My mom has a policy with assupol and I’m the premium payer. Policy started 1 July 2009, premium is 240 covering my mom 3 siblings and my niece, my two siblings turned 21 n were removed from the policy however the premium remained the same. When I call to ask why is the premium not going down I’m told my mom is paying R180 for 20 000 payout, n my sister R40 n her son 20, how did my mom get to pay R180 for 20 000 nedbank you pay 49 for 20 0000 this is day light ******* for a good 11 full years. When premiums fall behind the call me but when I call to enquire about the policy I don’t get assisted