Vodafone India — Cheated by not giving full benefit of rs 48 data pack of 500 mb for my number [protected]

On 01.06.2016 at around 01:00 am i got to know by customer care chat support and dialling *121# as well that if i recharge with rs 48 data pack recharge i will get 500 mb data for 28 days for my number [protected]. So as per cc guidelines i do the recharge by balance deduction but get 250 mb data for 7 days. During the late night conversation of late night after recharge i tell the cc executive by name shanoj that i only get 250 mb, he confirmed me the rest 250 mb and extra validity will be added in next 4 hour or earlier.
But the rest 250 mb is still not added, so i again chat with ayusha the cc executive around 01:30 pm on 01.06.2016 for that firstly he is denying for nay such offer. He replied me no such offer is for me. After telling him that i have every details in snapshot and the offer is still showing in by dialling *121#. He accepted that offer is showing in *121# after that i told him to take a complain for that, he refuses to take any such type of complain.
Now the question such a big brand with such renowned customer care service and such a poor service. They are accepting that offer is for my number but after recharging they are refusing to give the benefit. A single complain in also not taken. Please take it as a serious because day by day this type company are cheated as this way and forum please help me to get the resolution from cheater company vodafone.