How should I do to get refund from unauthorized transaction?

I tried to buy some products, but my Revolut card was not authorized. I have same experiences 5 times at the gym and 2 times at TESCO. I checked these transactions today, and I realized these funds were “reverted” and was not refunded yet. Help desk told me to give Revolut authorization codes. However, it is totally inappropriate to spend “a lot of time” to get an authorization code (and I am not sure whether I can get it or not.) Can anybody help this problem?

If the transactions have been reverted, it means no funds have been deducted from your account.