How to plant a grafted tree?

I’ve recently bought a couple of young grafted forest pansy trees.  They are in pots and are about 75 cm high from the top of the pot.   
The graft point is about 20 cms  from the top of the soil.  The branches are growing from the graft point at almost a 45 degree angle.... I’m not sure how I should plant. do I plant so that the graft point is just below soil level so that the main branch is vertical? Or do I plant as it is in the pot? In which case  I don’t think I’ll end up with straight and nicely shaped trees.   Perhaps I should just send them back? Advice would be much appreciated.