Kindly use the below details to correct the message center number of your line.
On your phone, kindly visit your message settings, select SMS or Text Messages, then choose...
Kindly share with me the error message you received while attempting to make calls and send sms, the details of your account balance is also needed for further advice. ~Ighedoise
I bought a Mifi device from your shop at Ikeja City mall
S/N 320513884549
IMEI: 867462052329632
and MTN line 08104170681
and I was told I will get twice the data I purchase...
I found a useful access point setting on YouTube that helped me out .
Then make sure you go to app settings and give Xiaomi SIM service all permissions
You can retrieve your NIN by dialing *346# on the phone number you registered with and it will cost you N20. To link your NIN, please dial *785# and select 1