I coated ours with mineral oil the day after it was installed a couple months ago. I was eager to see the sheen. The oil soaked in completely within days and I bought soapstone wax and used in without doing anything first. The wax looks good but it is soaking in too. I think it will take a few coats to really build up a coating. Enjoy your new soapstone!

Based on my experience with ours I'm wondering if you might have been overly generous with the mineral oil with your initial oiling. Seems you should have been able to wipe it down and by the next morning it wouldn't have been oily.

In a couple days when you're able to get back to it I'm guessing it might be okay - maybe just take a Bounty towel to it to remove any residue. If you still feel it's oily add some Dawn to warm water and go over the surface with a dishcloth. Rinse and let dry. Then you can buff in the wax.

I oiled ours after the installation, but since then I've been using a beeswax mixture I ordered from Holland Bowl. We've had our soapstone countertops & island for 7 yrs. now. I give it a buffing with the wax annually. That is it for maintenance and it's beautiful.

What kind of oil did they use? They should have used Mineral oil or a wax formulated for soapstone.
The oil does not soak in as the soapstone is non-obsorbent, it evaporates.
That's why some people prefer the wax mixture, it does not evaporate quickly.

Like mentioned before maybe it was applied to thick.

It also depends on what type of soapstone you have. We had a sample of Minas that loved the mineral oil and stayed a lovely black, but the Anasazi we ended up with takes the oil much differently. Parts of it stay oily for a few days and some parts evaporate quickly.