Do both!
It's hard, but you won't regret it. Lets say you study for 5 years to complete CS and at that time you worked for this company or another then you will have 7- 8 years working experience and a degree that will skyrocket you into the atmosphere (or stratosphere) Think of this, you will be 26 - 27 years old, with a truck ton of XP, amazing working portfolio and a Degree. Sounds nice heh?
Just take it slow with the studies 'even the turtle finishes the race' and talk to your employer so that they can understand that you are going to have to juggle a few things, you will see they will be more than eager to assist and help you on your way.
Alternatively, you could do both and take breaks in between. Example, work for this company for some time while you study, and if you feel you are overwhelmed you can always tell your employer that you want to go on a sabbatical ( 6 months more or less) to focus on your studies, think they will allow it if they are supportive and understanding. after 6 months you join them again and proceed with studies and work as normal.