Better to get rid of the black hole as that has too many other problems. Also, of itself it might not be an effective condition for inescapeability. Ditto having a super-deep atmosphere of 300-480 km, simply because the planet begins to be something like a mini-Neptune.
If your planet orbits an extremely active star, possibly a flare star, then its equivalent of the Van Allen radiation belts could be ultra-deadly. At least, they would have to be sufficiently lethal that astronauts had an extremely elevated risk of dying from radiation sickness.
Super-strength radiation belts could be more extensively developed around the planet. Many more belts and coming down close to the top of the planet's atmosphere. On the plus side, this would be a planet with incredible auroras. Night skies filled with beautiful shimmering veils of light.
While this does allow spaceships to actually leave the planet. Anyone in the vessel will be dead reasonably soon after departure. This could be six months later, but that's enough to stop interplanetary travel and, even, their equivalent of Earth-Moon flights.
The most suitable flare star could be a red dwarf. Yes that does most likely mean it would be tidally locked and the weather be extremely stormy.
This means your planet would be inescapable because of the double jeopardy of permanently bad weather and a shimmering shroud of lethal radiation.