The Internet Bill

my bill for january came...they sent me the bill yesterday day from 25th jan- 31st jan ......and the bill was Rs.33776($900,and its a lot for indian standards) for 5 days of which 2 days the internet wasnt working..i had downloaded 30 gb in 3 days.... i had opted for Rs.900($20) plan and they had billed me for some limited gb costlier plan,after a lot of tantrums ....the CRO's(customer relation officer) of my isp were very helpfull and they changed the plan to rs.900($20/month) and the best part is i offered some money to show my gratitude after all the work was done and they refused the money... just imagine my situation the whole of yesterday when my parents saw the bill....it would have added up to Rs.1,33,776($3000,this is huge money to be paid for 1 month in india atleast) because from feb 1st to feb 15 i had downloaded aroung 70-80 gb's...every 10 gb =Rs.10000,($400)