Improper Deck Footings Lead to Sinking Deck

 So, to start off, we are only renting this townhome, fortunately, and I don't have the burden cost of repairing this monstrosity. 

I noticed it, first upon seeing the property before even moving in, it was clear as day, half of the deck is sinking.
Now, I really didn't care, as long as you can walk on it and it's safe enough for adults (no kids in the house). And it is. 

The cause of the sinkage is an improper deck footing that was added sometime in the last few years before I lived here, that was installed to support a deck expansion. With the expansion, they retrofitted the existing footing & support post, which is a deep concrete footing, inside a black tube (pictured below). The added footings, however, were footing blocks, sat on top of topsoil, and have no structural value below them. In addition, this specific location is one of the lowest points on the property and is frequently muddy in the winter. Thus leading to the sinkage of the earth beneath the improper footing block.

Footing blocks should be installed below the frost line, my area is about 2-3 feet deep, not 2" deep.

Sinkage from the surface, on the left of the photo.
Where it starts to meet the stairs, also bows back up, due to there being more support distributed more evenly.

The beam that's attached to the post causes the mayhem. Comparing it to the beam on the left, which is level with a proper footing. You can also see the additional joists that were added here in the expansion of the deck.

The improper footing in it's full glory.

The original deck footing here. Uniform to the rest of the building's deck footings. Still holding strong!