Dpf Addative Tank And Light Off Status

[ianskill]

regarding 1.6 tdci,i posted while back regarding a issue with the engine sytems failure light on. I found a program that read the pcm and facm modules showing a dtc of addative tank low or empty. I worked out at £100 was far cheaper a garage doing it rather than myself. I have had the work done but after getting the car back the fuel seems to be going down quick like before when engine systems failure light was on. I asked the garage if the proceduer was done correctly and reset the counters,etc. they said done by the book. This program i have still shows the fault of low addative but saying the engine light is out. Is there any way the garage could have turned light out without refilling? thanks