Vodafone India — not getting the unlimited calls option!

I recently recharged for rs345 to get unlimited calls and 1gb/day for 28 days. I'm now in tamil nadu in vellore and the sim is not in roaming and i'm still not getting the unlimited calls option whenever i call it's saying you have low balance. I know the capping is done to 300 mins per day but i haven't used any of it.. Every time i try calling my balance goes off. I took this offer in order to get the calls option too so that i don't have to recharge my phone again and again. I would really want someone to look into this.