I have used vodafone 2G unlimited pack, signal strength is very good, also never faced problem which I faced recently.
It seems like problem is in my sim card, because when I used my friends sim on y mobile internet is working but not with my sim card, but when I called to vod customer care, after some time some one mr khan cut my phone.
Again I tried 5 times they have not attend my call yet. They should not recv call if they are not understanding problem, because of this problem I have to port my sim card to airtel.