[kictanet] Paybill charges

All Do we have extra charges for paybill through mpesa. If I pay a kplc prepaid bill of 180 and am charged 22 kshs then the cost on my end is 202 kshs. The i get charged an extra 36 kshs as a deduction to the 180 kshs token purchased hence my token is 144. I dont understand