Not credit the advantages/benefits

Hi,

Have recently purchase new phone of micro max, when i had inserted the SIM of Vodafone in my cell.
have received message that you have received 500 MB internet for 2 mons , which is activate with in 24 hrs (30-06-2014) .

have coordinate with them on regularly basis for the same but no one
answer me correctly, few says active today at this time or tomorrow , few says no offer is running for the same .
if i received the message for the same then why they denied for this .

i complain against of them for misguiding to the customers .

looking for the positive response asap .

regards
Anshu