I told my gp I caught pubic lice from public toilets she said to me know one cannot catch them from the toilets?

Person to person. They are spread person to person or from fabric that an infested person has touched (like sofa, headrest, clothing, towels, hats, etc..). The CDC website had no warnings about solid surfaces such as toilet seats and I have never known anyone infested from this type of contact.
Unlikely. Pubic lice are generally passed from another person and rarely from towels and linen. Pubic lice do not travel well on smooth surfaces, such as toilet seats. You are fortunate to have a smart doctor.
Pubic lice. Pubic lice or crabs (Phthirus pubis) can be spread by vector transmission. Wearing someone else’s clothes that are contaminated or infected towels, bed sheets or towels can give you lice. It would be highly unlikely to get lice from a toilet seat because they will die fairly quickly if away from a warm body. They don’t have the capacity to move on smooth surfaces.