The common name for Ficus benjamina is 'Weeping Fig', so it's not unusual that your tree exhibits pendulous growth. There are several techniques that allow you to coax this plant into a more nearly vertical growth habit. You can train a single leader to a stake or use a piece of wire to train it to the vertical. You can also terminate all horizontal growth by allowing all branches to grow to 5 leaves & then pruning them back to two leaves. This will keep your plant very bushy while forcing multiple branches to grow vertically. Chose the single vertical branch that looks best as the leader and remove all the others (vertical only). do not prune the selected leader until it starts to "weep". When this occurs, terminate it and choose one of the other branches that occur from dormant buds in leaf axils behind the termination point on that leader.

If you're confused and need more direction, contact me directly. I don't usually frequent this forum & only stumbled on your question.

Al

PS I have around 30-40 ficus up to 30 years old growing as bonsai, so I'm very familiar with the growth habits and training of this and other Ficus.