1998 Mercedes Benz 500sl V8 Two Wheel Drive Automatic 125,00 miles

I am having a problem with my convertible top. Currently I have the hard top on it, however, recently the convertible top switch and the roll bar indicator light starting blinking. Then the windows started malfunctioning, and then then oil spewed out all over the driver's side seat. Since then the convertible top switch doesn't work and my battery keeps going down. What can I do? Is it expensive to get it fixed.