How much speed you were getting on this plan
is it a special plan
if lower plan gives the speed that you were experiencing including unlimited free, then think of switching to general plans, which gives the same speed.
they may say, 20 mbps , but your wire would give the maximum of 12 mb if you are just using bb plans. if you opt for fibre, then your speed will be more.
please also see the present speed that is given for the plan. bsnl changes without any notice. if you go to selfcare bsnl website and login, you could know the present plan speed.
there is a thread in this forum, which discussed to how to access the information. i do not remember the link. if i know , i will get you that link.