First of all it takes all about 10 days to activate a single sim.Call drop problem.Net speed is also not good as compared to other networks.Supports calls only in volte devices.In other devices it requires app that is used only when data connection is on.Many people can’t use its calling facility.Worst downloading speed.Works like 3G and sometimes its 2G.Its a free headache for 3 months.Also its network coverage is not every where.It shows only one or two signals.It has also problem of customer care executives.They doesn’t receives our call early.sometimes they doesn’t pick the call.The worst condition is that it only works on 4G enabled phone.what about 2G and 3G users.