Anything built by the hand of man will fail, eventually- and you have a really expensive and complicated car- now it is time to pay Hans, the MB specialist with the Deutschmarks he needs-
The Owner's Manual for my 2001 SL500 says, "The roll bar can be lowered again after an automatic deployment by pressing the upper half of the roll bar switch (for at least 5 seconds) until the roll bar drive mechanism audibly engages. Then press the lower half of the switch to lower the roll bar". If you have not tried this, I suggest that you do.
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