@ijsa, I was on Vodafone India till 2015 and shifted that year (in June) to Idea Cellular where I remained till Feb 2018 when I finally moved to Jio. VF and Idea have the same level of QoS and I elected to move on to a modern network at a significantly lower price which was 50% less.
Trust me, both networks have been screwing up well before the merger was announced. If they die they have only themselves to blame.