Here are the methods of Dialog 4G Broadband wifi Data usage balance.
Check dialog Data usage by SMS
BB <space> Usage <space> <Home Broadband Number> and SMS to 678
Example : BB Usage 0112545874 to 678
Check dialog Data usage by Self-care App
Step 1: Login to Self-care app on your Dialog mobile and Select Home Broadband
Step 2: Select Data usage
Step 3: Anytime Data , Night time Data, Add-On Data and usage can be seen

Dialog selfcare app data usage
Check dialog Data usage Web/My Account
Step 1: Log onto http://www.dialog.lk/ and select my account.
if you dont have account Signup
dialog SignupStep 2: Select your home broadband number in dropdown

Dialog.lk web data usage