Airtel — Requested service not provided but deducted same amount of money

I got a SMS from Airtel to my no. [protected] regarding an offer that content Rs. 52 for 500 MB 2G DATA for 10 days 150 MB instant rest in 1 hr. I recharged from a retailer with 52, TransID:[protected]. I Got 250 MB data. I called to Customer Care regarding this 1st CC executive replied me within 1 hr i will get all 500 MB balance. After 2 hr i again tried they receive my call telling me to stay in hold and after few minit disconnect my call. same happend twice after that Customer care executiver are not receiving my cal. I just want 250 MB more as they offered through SMS.