My problem is solved.
I was inputting my current phone number which is my new number that I didn’t update on the app (it was never registered with the app) and that was the reason why it was seeing me as a new customer.
I sent revolut a message on their Facebook page (a messanger message) and they responded really quickly and after verifying me, they changed my phone number to my current one and once I put the correct number (registered with the app), the system saw that I was an existing user and let me log in instead of signing in.
If anyone has a problem with their phone number or email, i suggest contacting them on their Facebook page.
You firts get an automated message to contact the in app chat but I typed “can’t login to my app” and then a real person helped me to fix the problem.