Online stamp cart / discount system

Need a simple online / offline system for a small clothing shop where you can maintain a client database (address information, name, telephone number, email, bought items, remarks etc) and also be able to put a (virtual) stamp each time a client spends a certain ammount in the computer attached to that specific client / name. After a number of stamps collected, the client will be rewarded with a certain discount in return. The system should alert when a client requires a discount. I will provide a Microsoft Access document with the current client database and their address information. (not including the spend amount per client yet, will need to be filled in later)