SQL SERVER - LOG FILE SIZE PROBLEM:

I have created a database file and the log file with the size of 300 MB and 30 MB Correspondingly.

When the volume of data grows the log file size is reached to 6 GB. My database file size is only 400 MB only.

This is a severe problem and we need some assistance as to how to deallocate the space occupied by the log file.
Please also advice us on whether any shrink option should be used in order to control the log file size.