Had a very similar mark left on my rear bench seat when I purchased my car second hand, I found heat to be one of the best ways to improve it.
To remove the mark on my seat I place a large microfiber cloth over the affected area to help protect it, then with the use of a hand held steam cleaner applied heat for 25-30 seconds at a time then massaged the leather by hand to help reform/shape it.
It took about an hours work but the improvement was pretty good with only one deeper mark still being present now.
Worth a try
2014 Volvo V40 D2 R Design Lux Nav - Rebel blue, Winter Pack, Rear Camera, Rear Park assist, Tempa Spare Wheel, Upgraded Sound Multimedia, TV, DVD, Xenons, Full leather