IMO ,you should call them immediately and fall on your sword. You may find an expensive back charge on your account, when this goes bad. If it was only a couple of liters, it might survive. The gasoline will water down the lubricity of the diesel. That will be bad for the injectors, cylinders, etc. Not to mention that the flash point of the two are significantly different.
A quick Google search turned this up;
https://www.bellperformance.com/blog/accidentally-mixing-gasoline-and-diesel-fuel
1997 Porsche Boxster
2018 Porsche Macan
Threaded Mode
