The problems after changing Apple id
I have changed my apple id because I want to separate my ipad and my mum's iphone backup..
but after I changed to new ID, my old ID cannot use..
I tried to find my ID but it said the ID does not assist;
then I tried to create a new by using that email, it said the email has been used.
But I cannot use the ID..
What should I do?
Thank You!
iOS 9.1, Apple Id