Sounds as though this may be a retrofit steering wheel that was never wired up or a problem in the wiring/paddles somewhere. If this is a standard tiptronic type auto box the gear shifting is achieved by a simple earth grounding of the wiring on each shift of the paddle. This is what happens when the auto box gear lever is operated in the tiptronic mode so the the paddles are just a simple extension of this, as a make and break switch.
cj10jeeper produced a fantastic write up, with photos, on this some years ago which I followed to retrofit my own paddle shift. I also wrote this up as the paddle shift steering wheel that I bought on eBay did not work and I subsequently found out that SMG paddles are not simple switches but very much more complex(early E85's need SSG type paddles). I had to take mine apart and completely modify them to work. Several searches on this forum, using different headings, will find lots of postings on this subject. There is also a USA company who specialise in this conversion,
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