TLB Fault from Nationwide Trucks

Good Day I made a purchase of a Volvo TLB on the 5th of May for R550,000 from Nationwide Trucks. The TLb was emitting dark smoke but was assured that it was because it's a diesel engine and had been parked for a while, I believed that as it looked new. After making a payment of R550k (Wednesday 4th May 2022) i asked the mechanics (NWT) to double check everything if it was in order and will fetch the truck on the 9th,all this was verbally agreed. I however fetched the TLB on the 9th but when we got to the site,the propshaft broke because the bolts were not tightened, I fixed that. I decided to take the TLB for an inspection(JVH Werkswinkel) before taking it to the site for work,they found a lot of problems with the engine and the Turbo. I ask my self if I have been conned or was this an honest mistake? Have tried to communicate with them but seems they not interested with what i say.