As a buyer, how long do you wait until you request a refund?

So I’ve been buying singles for around 2 months and haven’t experienced many issues. However, I’ve had a couple instances where the app shows it as delivered and I’m still patiently waiting. Once the app says it’s delivered, you only get 7 days to request a refund so I typically wait until the 7th day and if it still hasn’t been received I request a refund.

Is this proper etiquette? In these instances I am in communication with the seller. There was one time where I requested a refund and the card came a few days later. But how am I supposed to know for certain that they mailed it out?