Substantiation, please?
For one thing, the Turks are traditionally enemies of the Kurds, who want to establish their own state within Turkey's borders.
So it's not surprising (the enemy of my enemy is my friend) that Turkey would support ISIS, if not actively, at least passively.
But you're not providing any factual information to support the allegation that it actually is happening.
And it's obvious that the oil is going over land to a country near ISIS territory. That means Turkey, Iran, and possibly Jordan. Considering the friendly relationship that Iran has with Assad, I doubt they are buying oil to fund their opposition. With Jordan requiring travel through area's that ISIS doesn't have strong control over that's also not likely, at least not for their main source of funding. That leaves Turkey.
If you can't provide substantiation for this claim, perhaps you should be more careful in how you choose your wording -- especially when making rather loaded and incendiary allegations, of this sort.