Gross negligence in inspection report

i bought a car from Webuycars, based on a dekra report (Audi S5 from PE) that only listed 1 item, nl. oil leak. Then on taking delivery of the car discover, the entire front suspension of control arms are all worn out and in need of replacement, including leaking shocks, and front tyres are worn to steel on inside ridge. How could this be missed on an inspection? gross negligence. What else was overlooked if these blatant items are overlooked? Now i'm in for R20K worth of costs that i was not banking on or aware of at the time of purchase.