Final Gravity is too high

This is our second batch of beer so hopefully it is something simple.
Brewing a dunkelweiss from a Brewers Best kit.
The kit had LME and we followed the directions.
Starting gravity measured at 1.050
About a week after sitting in primary, gravity read 1.024
Fearing a stuck ferment, we went to out local brew store. They gave us another packet of dry yeast and said to sprinkle on top, stir and wait.
After four days, I took another gravity reading and it reads 1.022
Instructions call for FG to be 1.010 - 1.014

The fermenter is in our basement with a temp between 68 and 73 degrees.
There is very little bubble activity so I am unsure what to do next. Any ideas, hints or tips? Maybe even a SWAG?

Hope this helps....But my second batch of beer was a darker beer. What I was told is that darker beers sometimes will finish at higher gravities. Here is the forum where i posted, mine was a stout so could be different.
https://www.homebrewtalk.com/f39/uhhg-help-1-020-a-102389/

Some beers just ferment slowly. I would give it another week and take another sample.