Battle net authenticator issue ( relink to account)

Hello maybe someoen can help since i keep getting the run around from the the GMs . so i migrated my authenticator to the mobile app no real issue there …
When the system asked me to log back in a couple of days later it asked for the authenticator code and would cause errors, so only thing i could do is use the option remove the authenticator which i can now log into battle net.
But still i want to be able to use the authenticator.
Note i have cleared cache , uninstalled and reinstalled multiple times changed browers etc , notifications are on.
When i try to link the authenticator i enter the serial no problem , then go and get the code and it says code is not valid …
Gms keep telling me to do things i’ve already done and specified ive done in my past messages .
Has anyone had this problem and been able to get it fixed , can i get a brand new serial or something ?