Unfortunately, unless you have a friendly dealer, upgrades are not done unless you complain there is a problem and MG agree to pay or you have to pay.
I believe you have a fault that should be fixed under warranty. You could try a Factory Reset of the Infotainment System or disconnecting the negative terminal of the 12V battery for 10 minutes. Please read the Wiki before you try that.
However if the car was sold to you with this fault then you should get the dealer to fix it before trying the above as some Posters have had problems afterwards.
Was your car 'unbound' from its previous owner?
For the USB cable you need to use the lefthand socket (USB-A). Can you please confirm the Bluetooth link to your phone rather than an Andoroid phone by looking at the car's Bluetooth page.
You can restart the infotainment system by holding down the home button for ag least 10 seconds but you probably have restarted it already by powering down the car.
@siteguru, can you please comment.