How can we improve WHMCS?

Would it be possible to introduce some sort of voucher scheme, (similar to supermarkets)?
For every £1 a customer spends, they earn 1 point.
After a period of time (let's say 3 months for example), if the customer have 150 points, they get issued with a voucher for £1.50, and 150 points is deducted from their total.
If the voucher is not used within a time frame, then it will expire.

Would this be possible, or dose such a feature already exist?

Thank You.