Height always seems very objective in adverts unless they have a LHC I would take the advertised height as an estimated height not an actual measured certified height. If height very important then I would be taking a measuring stick at viewing especially if the pony looked big on the videos. It won't give you JMB height but it measures 15.2 on the stick it is probably not going to measure in a 148 even without shoes.
I expect the pony has grown since it was 6. There is a reason that LHC are not awarded until the pony is over 7 and that is because they can continue to grow up to that age. If the hooves were severely trimmed and perhaps the pony freshly clipped so less hair on the wither it might have squeezed in at the original measuring and perhaps then grown a couple of cm.
I think to get a refund you have to prove that the seller knew the pony was over-height and would not measure in, which is probably going to be hard to do.
I have a native pony and it was important that he would measure in, I got him at 5, 13 years ago and I am pretty sure the vet measured him at the vetting. Advertised as 14.1 but he looks tiny compared to others in his class, he is a forester and the Connie's look huge in comparison. He looks so small that my non horsey mum who came to show to see him asked why he was not in the small breeds class. My friend who has a 143 Connie said she thinks my forester would measure in at 13.1, I measured him on a stick and he is indeed 14.1 in his shoes.
