Can Green Dot MoneyPak card be reloaded or reused?

I bought one for 5$. I used all the money in it already can I go to the store and give them money to load it into the card again or do I have to buy a new one?

If yes, Can it be done online and how? Whats the point of having a Green Dot MoneyPak if you have a bank account why is?
Update: @Common sense .. I did in the wrong section and got only one answer.