Pathetic terrible ,no service from WhatsApp

I installed a new device with the same phone number My chats were there on WhatsApp all the time Backing up all the time before

Now all of a sudden I am not given opportunity to install and recover my chats on WhatsApp Secondly WhatsApp does not care I cannot get sms verification code option two calling when I try it says no no reachable and my Service provider MTN said WhatsApp is not telling the truth since AK receiving messages and calls