My parents never experienced this with other new doctors before. This horrible clinic seems to have this policy to get more money from insurance companies.

Your parents have been lucky in the past. It’s very common and not a money grab to use the billing code for a new patient visit because your parents did in fact have a new patient visit. It’s frustrating that this wasn’t made clear to them at the visit, but the clinic did bill appropriately & an insurance review isn’t going to change things. One thing to be aware of is that there is a very narrow range of topics & labs that will be covered in the preventative care visit & if other health issues are addressed at next year’s wellness visit, it also wouldn’t be coded as the preventative care visit. In the future, let the receptionist/nurse/dr know in advance that you are only there for the preventative care visit.