Dekra report not disclose that an engine has been tampered

I logged on their website on the public holiday 09/08/2024 at night, I saw a live auction that is going to close on the next morning, i chose a white Nissan Micra, read out a dekra report and I bid for it, on Monday I went with my mechanic to double check the car before i transfer the money.

He examined the car, and he found out that an engine has been tampered but I t was not disclosed on the dekra report and he advised not to continue with the deal because that mean I will find lot of things that are not on the report and the car will end up costing me more to fix it. Then the sales man told me tha I won't get my money back if i am pulling out, I told him that i was not informed about the major problems in the car