Hi there Hsaraiya,
I will be happy to assist you today. There is a possible action.
In case of the "Using the charger in the month":
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You can get your money back for the days you haven't used that charger.
In case of "Before the month has started":
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You can get your money back as you have paid in advance and you can take your money back if you don't won't to use it anymore.
These are the possible ways. If you are still experiencing issues then just reply to this thread I will be happy to assist you again.
Warm Regards,
Acme Gamer