Vodafone India — disconnection of benefits before offer expires

I have done recharge of rc373 on november, 2017 with validity of 84 days. But they disconnected voice calling and data benefits on 31st jan, 2018 before expiry of 84 days. I have called customer care on this issue they were saying that offer is valid for 70days and expired on 31st. But when i did recharge rc373 it is validity 84days &got confirmation from vodafone care. Now how it changed to 70 days validity. I didn't get any solution even after talking with vodafone customer care executive several times. This is cheating by vodafone. Please do the necessary actions to compensate me for the services lost due to cheating activity by vodafone.