Hm.. Unfortunately.. Indoor Trees do not exist. All plants should be outside as uch as possible, unless you have a very good climate control system mimicking situations outdoors. Some species cannot sustain themselves in the outdoors because they have been moved across climatic zones and therefor must be brought in for part of the year. But in general: They should be outside when the weather permits this.
Serissa .. What can I say. They are not the easiest of plants to keep, and in a way it is almost a crime to see how many of these "bonsai" are for sale.
Do post a picture so we can have a look. Hit reply. Upload a picture that fits the size specs in the upload space, and submit. Should work fine.