Have you ever tried to call 1961 on your mobile phone? This is the short hand notation of 1800 180 1961 (the call center of Aaykar Sampark Kendra ASK Helpline). All cellphone operators would connect to the same without any issues except Vodafone India. I had reported this to Vodafone on friday through their social media on September 4. Some one called me and confirmed that it is not just my Vodafone number but a lot of numbers are affected as they confirmed it. The issue has been escalated by them. At least till this point of writing the issue remained unresolved by Vodafone and still in progress.
So if you need to call ASK Helpline meanwhile you may need an alternate cellphone network or a landline to call the same.