Hello, Bitrefill here. You guys did a good job explaining, so I am going to paste the answer I put on the Trustpilot review this user posted:

Hello, your transaction was done from unconfirmed outputs. You shouldn't use a wallet that allows you to spend unconfirmed balance, it's risky for us to accept them with zero conf.
We will see if it's worth to include this requirement detail together with the minimum fee and no RBF.

If someone appreciates Bitrefill and wants to offset his bad review on Trustpilot, it would be very welcome: https://www.trustpilot.com/review/bitrefill.com

Something else. Instead of paying 30 sats per byte like you did, think in using a wallet like muun which is an onchain wallet that allows you to pay lightning invoices via swap, so you will get instant delivery at Bitrefill by paying only 2 or 3 sats per byte.