Reactivation of old SIM card. Need to know the steps?

[Mehak_1]

For some reasons I switched off my old SIM number but now I'd like to use my old number again; how do I reactivate it? Can anyone tell me the proper & precise steps?

 

[Titillating]

Call your service provider or visit one of their retail stores and speak to an employee there. There's really no other way.