BSNL SIM
Sim is not working properly

I am a customer of bsnl prepaid i had portout my sim in bsnl from vodafone near the month of february starting but after some time i felt that my sim is not working properly that have facing a lot proble of signal but all other sims have no problem on that time when my sim is facing signal problem and this temporary problems occuars me a lot problem to me a many times

please help me