You can check the remaining credit balance on your account using the My Digicel app as follows:
View your balances by clicking here.
Step 1: Click on “Connect with your Digicel ID”
Step 2: Select the menu in the top left corner
Step 3: Click on "Account & Balances"
Step 4: At "Data Balance" you can view the amount of MB's that are left
Note: You can also see your data balance from the home screen. The green part is the remaining data and the grey part is the used data.