They hacked my cell phone

Yesterday my cell phone was hacked, I was installing from the browser an app, super, to watch movies and tv, when I downloaded the APK, a malicious software was also downloaded, and a mirror was shared on the internet, somewhere in the world they saw they listened to everything I did from my cell phone, they even came to control my cell phone, they closed the apps, they opened apps, windows were shown for me to type the password, but the window was not the same as the apps, I already began to suspect and I removed the SIM card, and disconnected from the wifi 🛜, today I took it to a technology center, which flashed my cell phone, why was it totally blocked to format it, I don't know, when I tried to enter, it came out, I had to pay for them to do that process, and my cell phone was fine, what did they do with this malicious app, they changed the passwords of Emails Nequi Bancolombia and they were trying to enter my credit card NU BANK, this NU BANK app, was the one that reported me by sending a message, when I tried to enter the app, a message came out, your account is temporarily blocked because an unknown app, is trying to enter your account, immediately call NU BANK, and they helped me. I'm telling you that so you don't fall