Car with manipulated km stand purchased

Hello guys, I bought a 850er 10V with 144 hp at the end of 2010 with then ~ 142000 km on the speedometer. Now I found last week at Volvo Pedia an article like you can read out the km stand in the instrument cluster at the 850er and so the disaster took its course. Curious as I am now, to the car and tried out. Well Ergebinis after three times reading always the same. It is missing quite exactly 100000 km. I then researched and turned my car upside down to after There was no service booklet (now I know why). Well, sometimes the search is worth it and I found an old Tüv report, on which the car had already ~195,000 km down in 2008. Then I found the previous owner and contacted by e-mail and see, the car had already run over 200000 km on sale. Everything packed up and returned to the guard and report. Now to all evil stands also the timing belt change Well, parts have already been ordered and come today. Now the real question: Has anyone ever had such a case? I have already put around 10000 € in the car with the purchase price. Among other things, a gas system installed and so on. Should the fraud be proven, what can I assert about compensation? Conversion will no longer be possible after 1.5 J. LG Olca