Airtel — prepaid service ending 1 month prior to date

I had recharged my mobile on 4thjuly17 with rs.399 and by mistake had recharged it twice.in last week of july i could not make calls for 7-8days. I called customer care and enquired about the plan and was told that it was unlimited calls for 84 days and its last date will be 1st oct., double recharge cannot be considered, thats ok. Now since 28aug. I am told there is no balance. I called customercare on 1st sept. And was told there was some technical problem and call services will start within 4 hours. But no servce next day also, again i called customercare and was told that there was no balance. When i asked about the plan he said that plan is for 84 days but was not applicable on my number. How can the same plan be different for different nos. I want full 84days service.