I suggest you inspect what the dealer did to seal it. Can you tell if the sink is pulling away from the counter?
Look underneath for metal clips that are screwed into the underside of the counter top and lap over the edge of the sink. Something I also like to do is seal the top edge sink where it meets the counter top from the top side - inside the sink.
When you say "It also is not counter height...", are you saying the sink is lower than you prefer, yet it is in fact mounted in the counter top? Maybe what you mean is the counter tops are lower than you prefer or lower than standard - like in a home? If the latter is the case, that's a difficult fix except for sinks in an island where technically, the island could be raised.