Each application is based upon your credit status at the point of that application.
As credit status fluctuates over time depending upon a customer's behaviour this can lead to differing decisions, even if you already have an Argos Card or an existing Argos Monthly Payment Plan.
Each Argos Monthly Payment Plan is for a specific item(s) and works so that you only borrow what you can afford to pay back in monthly instalments.
Any decision will be based on the goods being purchased and if this is affordable, rather than on the total amount that you could borrow.