Hey, here is some guidance for you in the future...
If the product develops a fault within the first 30 days, you are entitled to a full refund from the retailer. Without much questioning.
After 30 days you product develops a fault, you should return to the store to request a refund or an exchange. However, they do have the right to attempt a repair an item in the first instance. I would strongly advise that the repair is booked by the retailer rather than doing it yourself, just to avoid any issues.
If after the repair attempt fails, they may convivence you to try again. However, after one failed repair attempt it is your right to request a refund or replacement item.
Argos is very bad for returns and I had an experience with them recently. After a failed repair attempt I requested a refund and the store and regional manager refused, saying they are entitled to continually send it off for repair. To resolve this and claim my refund as stipulated within consumer law, I had to escalate this to central argos management who forced the store manager to issue me with a refund.
Do not ever blind faith follow what a store tells you are your consumer rights. They will play every trick in the book took keep the store balance sheet 'good' so they appear high performing to management.