Yes, I know, you have said that. As I said already, Abraham knew he would not inherit the land in his lifetime. God told him such. (Gen. 15:15-16) "And thou shalt go to thy fathers in peace; thou shalt be buried in a good old age. But in the fourth generation they shall come hither again: for the iniquity of the Amorites is not yet full."
And at that same time God outlined the boundaries of that land. (Gen. 15:18-21) "In the same day the LORD made a covenant with Abram, saying, Unto thy seed have I given this land, from the river of Egypt unto the great river, the river Euphrates: The Kenites, and the Kenizzites, and the Kadmonites, And the Hittites, and the Perizzites, and the Rephaims, And the Amorites, and the Canaanites, and the Girgashites, and the Jebusites."
Are those boundaries earthly boundaries? Are those rivers earthly rivers? Was that land possessed by the various peoples listed? Did God make a covenant with Abram concerning the boundaries of the land he and his seed would inherit?
As to your question: did God not keep his promise to Abraham, as well as to Isaac, and Jacob? Of course God will keep His promise. I expect Him to, just as they expected Him to. (Heb. 11:13) "These all died in faith, not having received the promises, but having seen them afar off, and were persuaded of them, and embraced them and confessed that they were strangers and pilgrims on the earth."
And, concerning (Heb. 11:16), "But now they desire a better country, that is, an heavenly:" That doesn't indicate a fulfillment of their desire. In fact Paul is writing many many years after Abram, Isaac, and Jacob. Yet he says, 'but now they desire'. Just because they died and are now in Heaven doesn't mean their desire for a heavenly country has been met.
That desire won't be met till the earthly land described in (Gen. 15:18-21) is given and experienced by them for an inheritance. It will be earthly and heavenly because it's origin will be from God, from Heaven. "Thy Kingdom come, Thy will be done in earth as it is in heaven." (Matt. 6:10)
Any thing short of that, and God will have broken His Word. And that won't happen.
Lees