I have been using bitrefill since 2018 and never at anyone point have they taken my money and the refused to provide me with what i purchased. Even at times when I sent them the wrong prepaid mobile number, they would provide a page to request for refund to my account.

Stop misusing the word SCAM.
This should not be a scam accusation but rather you being impatient and incompetent. To avoid suffering from double spend attacks which are easy to perform in such auto purchase platforms, They insist that your transaction must at least have 1 confirmation.

It's not their fault that your transaction took over 12 hours or 24 hours without getting confirmed. Next time learn to use higher fees if you want a quick purchase.