Vi - Poor internet connection for last 3 months

For last * months my internet services have gone from bad to worse. I've paid for *G service but most of the time my sim shows *G connectivity. I've gone through my phone settings and there's nothing wrong with it. The company helpline services are of no use the make excuses instead of giving actually solution or doing anything about the complain. For last few days my calling services have started misbehaving too and its not in just the area where i live its the same wherever I'm.