How can I tell if the emissions fix was secretly done on my Volkswagen Eos?

I recently took my 2010 Volkswagen Eos TDI to a Volkswagen dealer for a minor service. They told me the software fix was now available but I asked them not to install it without me having done more research into what the fix meant first. They reluctantly agreed but I'm now having problems with the EGR. Given the similar experiences of others here and the potential link between the software fix and EGR failure, how can I check the software was not installed without my permission?
Less torque at low revs, increased fuel consumption, frequent DPF regeneration, glowplug light coming on signifying choked EGR are all signs of the NOx emissions fix having been carried out.
Answered by Honest John on

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