is it just a shop or is it a mobile phone repair center as well? if it's just a shop, a generic model of any shop would do but if it is a repair center you have to build up your database. i'm more than happy to give you advises but i need some initiative from your side... to design a database solution you need to map the processes first... try to create an ERD diagram to start with something and later you can adjust it.
You probably have more requirements than just the name, right? Walk through the requirements, think about the things that define those requirements as pieces of data and how those pieces of data relate to each other. You should be able to make a pretty good start just walking through that process.