I don't disagree with MF's post above but you need to be quite clear why you think they are neglected.
Yes, pot bellied pigs are prone to Entropion, which maybe a result of obesity but not always. If the pigs are over weight then losing weight might help and an operation is possible. However, if they have been seen by a vet then unless you have reason to or are qualified to disagree you are going against professional advice.
Pigs need shelter, food and water. They should be able to express normal behaviour and there may be some debate as to whether being kept indoors provides that but plenty of pigs never go out and they root in straw instead. Obviously they do have other pig company. They should be free from pain, injury and disease but being realistic pigs get sick or might injure themselves and as long as the environment they are kept in hasn't been the cause, the owners responsibility is to seek rapid diagnosis and treatment. In this case you say a vet has been.
If you really feel there is a welfare issue then you can take action along the lines of MF's suggestions above.
Obviously, if a vet has attended any investigation will involve speaking to that vet.
There is no reason that a CPH has not been given for a garage. people get them for their garden.