First you should check the unit of bandwidth and download rate.
It is very likely your bandwidth unit is mega bits while your download unit is kilo bytes
Note:
8 kilobits is 1 kilobyte
A 1 Mbps (Mega bit per second) connection can sustain approximately 128kBps (kilo bytes per second).
Make sure that your program is using the same units (bits/bytes) as your connection.