Airtel — wrong charges applied in postpaid bill

i have postpaid connection with the no.[protected] from 5 months.from the begining i have suffered lot.firstly inspite of CUG connection i have chrged for internal calling and till now i have not get any waiver insipte o[censored]r customer care executive,at bharti house ahmedabad, have forward the msg.And there is now matter i have shown in the last two bills that i have not been refunded the activation charges which should be refunded by you per month Rs.100.there is another quary is i have charged Rs.500 for just 44 mints show plz reply me how it all were happen.