Hi Jaydhie. According to Chatr:
If you fail to make your full monthly payment, you cannot use the account balance or any services associated with your plan. After you successfully make your full monthly payment, you will be able to use your account balance.
If you don't pay your monthly plan fee for three consecutive months your chatr account is deactivated and any remaining balance expires. Source: CHATR FAQS
Hope that answers your question.