That's why I always overfill my pots. Did you just recently pot it? If so can you reach down in the soil and pull the rootball up while someone else tamps the soil down. Or if its big enough can you just pull it up by the stems and tamp the soil yourself. I've done that with house plants.
That 8 inches you could use for roots an extra year or 2 instead of filling at top.

When I find this problem with pots,I remove root ball and plant and add enough new mix to the bottom of the pot to bring back up. Al

What Al said.

Ah... I was hoping for an easy way out. You guys are going to make me work. :-)

Figs are like weeds. They will grow, but if this is a designer fig, you should baby it with all kinds of a bigger pot and smother it with love.... Wrong! Figs are weeds! Get it out of the pot and put it in the ground. It will thrive, but keep it away from your house foundation because it has serious roots.

I know that didn't help... but I tried

Suzi

Suzi: I didn't know about the roots being invasive. I think I'll keep them in their already large pots. The figs are a Black Nigra and an Italian Honey; I don't know about them being designer or not.

We have native? figs that show up anywhere where they are difficult to remove. I now have a tool that cuts on the pull stroke which I use to go inside of a desirable shrub to cut off the fig as close to the ground as possible. I cannot kill it, so just remove as often as it shows up. Al