Hi Aaronjc,
The tree you have is a Carmona (aka Fukien Tea), and sad to say i'm pretty sure it's dead.
But don't be shamed, Carmonas are very difficult to keep alive. It's a tropical species and require very specific living conditions. In England these trees can't survive outside because they require a minimum temperature of 15 C, so they are often sold in nurseries and garden centers as "indoor bonsai".
The truth is, it's also very difficult to create the right conditions indoors to unless you want to live in a sauna. They require a humidity of over 90% and over 10.000 lux.
Nevertheless these trees are still very popular because they grow very fast and are very cheap to create in tropical countries like Thailand, Vietnam or China. Because they are so cheap, they are also treated very bad. They are planted in poor soil and transfered to Europe and the US to be sold by people who don't know how to care for them properly, giving them an even worse chance to survive.
For this reason most people who are really into bonsai usually look for native species, or ones that can be kept outside in their natural environment. Like Junipers, Oaks and Willows e.g. in the UK.