How can I import and manage store credits for multiple customers?

Hi, We are urgently looking for a way of importing approx 500 customers with store credits (dollar value) so they can redeem the credits and top up with credit card for purchasing from our company stores. We would need to be able to manage this process with bulk imports of customers (employees) and exports (when required for reporting) Also bulk additions of credits for specific customers - for example anniversaries and birthdays.

Look forward to your suggestions..