BSNL — Blocked my BSNL sim without any warning

Address:

Kannur, Kerala

Bsnl blocked my sim one day without any warning. When I contacted the customer care (the most horrible experience of my life, wait hours to speak to executive ), he told that my sim was taken in 2010 and I had to register again. I so they should ve atleast informed through a SMS or a call. Why they are spending a whole lot of money on advertisements if they don't know to retain existing customers. Horrible .