Airtel — completely dissatisfied with airtel customer care and store folks

I was using a airtel post paid number from long time registered in bangalore. Recently when i visited my native (Assam), my mobile phone was lost and i have asked customer care to block my sim. As i will be staying in native for couple of months on health ground, my sister collected the sim from one of the airtel store in bangalore and in the store they told her like the sim needs to be activated in assam. When i visited an airtel store in assam (North lakhimpur), they told me like they can't activate the sim. Then again my husband visited another airtel store in bangalore and explained the whole scenario to them, they told they also can't activate the sim. And, they asked us to send a mail to customer care. I have sent couple of mails explaining my situation to them but those guys initially told me they will activate. But later replied again saying they can't activate. These guys kept on dragging me from one place to another without any proper solution. They don't understand customer's issue and don't understand that so many customer things are linked to the number