Starhub Mobile - Frequent call drop problem

[apps21]

Is anyone experience call drop on Starthub. Call will never reach to cell phone and you'll either get a SMS alert for a missed call, if voice mail is not activated.
I've this strange issue which starhub is unable to resolve in last few months and wants unspecified month to help me to notify them whenever I've a call drop.

Even after providing such patahtic services, shamelessly they want to penalise customer to termiante this patahatic service. A ggod example of modern age service companies...