Haven't had a reason to call the customer care in three years of my using the service 😉
Except for the latency /routing issue, that said I barely have faced any downtime in the past 3 years if at all. They respond to complaints within 2 -3 hours, which imo is not bad. Hence I'd say bsnl
Airtel screwed my billing multiple times, before I actually realised it 😛
Ya I guess our opinions are based on our experiences which may not be the same for everyone. My previous BSNL connection was down for a week without any guy taking ownership to fix it. Left me pretty frustrated. Have had issues with Airtel as well, but it was more to do with plan migration headaches rather than service downtime