Action 23k1 Expired? PPD Exchange Details

Hello, I have a Volkswagen A4 TDI with a 2.0 engine and 170 horsepower. The previous owner's mechanic informed me last summer that recall action 23k1 was due on my car. Also, I received a message from an Audi mechanic in another online forum who stated the same thing (they definitely checked based on the VIN). However, at that time, the car was unfortunately unregistered, so I didn't have it done right away. Online, it also said that the recall action had no time limit...
I just went to the local dealer, and the friendly lady said, after taking a quick look at the umbrella, that nothing was open on mine. When I asked if the promotion had been discontinued, she couldn't tell me anything (even though it's a very large retailer), she probably didn't know about it (or didn't want to acknowledge it ).
At home, I searched online and found the official recall page on Audi's website, but there was no entry (anymore) for my VIN. Presumably, the lady only searched there as well. If you ask Audi whether this campaign has been discontinued, you are immediately redirected to the local dealer, of course with the same answer . According to a forum post, it must have still been available in the spring, because someone received a replacement then.
I should also add: I checked the engine, and I definitely have the "bad" PPD 073M injectors in it!
Does anyone have any information on whether the offer has been discontinued, or any suggestions on how to still obtain it?
My car is shaking when idling and emitting a lot of smoke at traffic lights. My current understanding is that this is caused by carbon buildup. Otherwise, the engine runs quite well. Therefore, I would like to have this issue addressed along with other maintenance tasks, as it might resolve the underlying problem.
Here's the translation:

"One more question: would you prefer the US cleaning method or replacing the injector nozzle? The main work seems to be the disassembly itself. Is the repair kit available from other sources besides Audi, and at a lower price from the original manufacturer? I haven't found anything about that."
Thank you.
Andreas.

This action was likely limited to a period of 7 years after the initial registration - too bad!