Can’t use my dPoint points?

I've got like 1,300 dPoint points (I'm rich!) and I tried using them at a convenience store the other day. It didn't work.

I then downloaded the dPay app thinking the dPoint app was just for collecting points. I tried the dPay app today and it didn't work again. It said insufficient funds. I was trying to buy a 180 coffee.

About 1,000 of those points are set to expire at the end of the month.

I've used AUPay, Rakuten Points, MerPay, etc. all without problems. What am I doing wrong with dPoints?

by golfball509