Airtel prepaid card
My sim got recycled

I have bought a sim 2 yrs back.and inbetween i didnt use that number..and before 2 months i used that number and they charged me 50 paise per msg.and when i tried using that number, it cums as sim card registration failed.wen i called customer care people they said like number willget recycled if sim is not used for 30 days.i am shocked hearing this info..please help me in getting back my numbe