Is this their 'Complete Savings Programme' ?

The Argos page I looked at said

Often shop online? Excellent! The Complete Savings Programme is for people like your good self. It’s a completely brilliant membership scheme that gives you benefits at over 650 major companies, including Argos, Trainline and National Express:

Get a monthly bonus, a welcome reward and up to 20% off gift cards
Get up to 10% cashback every time you make a purchase
When you’re next shopping on argos.co.uk, keep your eyes peeled for a prompt about the Complete Savings scheme. Joining costs just £15 a month. Bargain!
https://www.argos.co.uk/help/faq/72466

It doesn't explain the 'welcome reward' - maybe that's how you got 19% ?

Whenever I read 'up to' in an offer, I move on.
I'm only interested in 'at least'.