Airtel — not given promised validity of 56 days against recharge of rs. 399/-

I receieved a message at 5, 27 p. M. On 31st october in my mobile to recharge for rs. 399/- to get free calls etc. Along with 56 gb for 56 days. I got the recharge done for rs. 399/- instantly but, unfortunately got the instant message on my mobie that i have been provided the benefits for 28 days only. I lodged a complaint on 1st november. Ref. No. Was cbnrv[protected] at 19:58 hrs. A reply came on 3rd nov, that recharge benefits have been put in my account but it is not clear with me whether the benefits are for 56 days or for 28 days. Because i wandered to every nook and corner but could not find the answer. Can you tell me what validity i have got - 56 days or 28 days and also can you tell me how to reach your customer care/complaint over phone directly without any hassle? Shikharendra prasad das. Mobile no. [protected]