Study says that if u had the gardasil vaccine, but were already exposed to hpv types 16+18,there is an increased risk of precancerous lesions? true???

No: That is not true and does not make any sense medically. The vaccine does not increase the risk but may not prevent the infection if you were exposed to the virus prior to vaccination.

That is expected: Vaccine is meant to prevent acquisition of HPV infections. So if you already have exposure to HPV before receiving the vaccine, then it is too late to have any benefit from the vaccine. But it is not any fault of the vaccine in that case!