samsung A52 having visual voicemail setup error

I had this phone for around a year. I setup my voicemail already and I am able to access it by dialing the VM number and enter my pin. 

I have this visual voicemail app that came with the phone and I have tried many times try set it up. 

during the setup procedure on voicemail, it dials to VM number , I enter the my pin, able to access voicemail then I hangup to continue setup process on visual voicemail app . next , I get an error. "An account verification hasn't been received yet"

I tried numerous times and failed. 

I need help from someone but I don't want to call ATT and start from scratch again. you tech support people aren't able to fix this problem but I can't get a hold of the experts neither. I am stuck with this issue and thinking about quitting ATT and go to Verizon or even Tmobile.