A:Answer I think you are confusing two different types of cards used in smartphones.
There are two different "cards" for different purposes.
First, there is the SIM card, which is needed to make phone calls, send text messages etc via the cell phone towers. And that does come in a NANO, and a Micro size. The phone comes with a SIM card for use with Simple Mobile.
Second, there is totally different type of "card", the data storage/memory card. There is no such thing as a NANO size for that. It comes in different sizes, the smallest size (and what modern smartphones use) is a Micro size ie MicroSD (unlikely)/MicroSDHC/MicroSDXC (depending on the storage capacity of the card). Most likely the phone does not come with any data storage/memory card. You have to find out the maximum capacity the phone will support and not buy a card with greater capacity than that. Just about all smartphones now support at least 32GB, which is a MicroSDHC. Doesn't have to be any specific brand. (SanDisk and Samsung are common). Although it doesn't have to be any specific brand, the speed of the card does matter. If you put a slow card in the phone, it will probably tell you so. Buy the fastest brand name card you can afford.
Look at some pictures of a SIM card and a MicroSDHC/MicroSDXC card, they look very different.
Re " the one MicroSD I did buy is too small for the slot " , you might be looking at the wrong slot ie the SIM card slot. Make sure you're looking at the storage/memory card slot, because almost certainly it takes a MicroSD/MicroSDHC.
Hope this helps you.
