Valid Discount Coupon Being Deactivated

I was just sent a email telling me that my coupon of R150 off a purchase of R350 or more valid till the 31/03/19 has been deactivated due to takealot.com reaching there redemption level on coupons.

But how can they reach there redemption level if active coupons have not been used yet? Very unsatisfactory, as I have items in my cart which I wanted to use the coupon on specifically, I cannot use it on now.

Very disappointing experience as takealot.com was my favourite online store.