Airtel — migration from aircel to airtel

I have applied mnp from aircel to airtel and visited the airtel office in kodungaiyur (Chennai-118) near kodungaiyur police station and the said they can ony migrate to airtel postpaid. After insisting them for prepaid they are asking to pay rs.150 for new prepaid sim. I enquired airtel customer care, trai websirte and also in airtel website it says that the sim card is only rs.19.

But airtel store is asking to pay rs.150. I asked them why we have to pay rs.150 and they replied that they have got the sim from distriutor so they are charging rs.150 for all mnp customers. How is this fair. Please look into this issue and pls help us in migrating from aircel to airtel prepaid.