Can the dead hear us though God said in one place that dead people don't hear us?

There is no contradiction between the Qur`anic verses and the fatwa.
In his commentary on the Sahih of Bukhari (vol.3, p361-362), Ibn Battal wrote, "At-Tabari said, ‘The correct opinion on this issue is that both of the Prophet's traditions are authentic based on their narration by trustworthy chains of transmitters. Thus, it is obligatory to believe in the two traditions and acknowledge that God enables whoever He wishes from among His dead servants to hear whatever He wishes from the speech of the living; He enables whoever He wishes from among His dead servants to understand whatever He wishes and He bestows His blessings upon whoever He loves from among them. God also tortures the disbelievers in their graves and those who deserve punishment in whatever manner He wishes. This has been transmitted through authentic traditions reported from the Prophet (peace and blessings be upon him).”

God’s words in the twenty second verse of the chapter of “Fatir”, "Indeed, Allah causes to hear whom He wills, but you cannot make hear those in the graves" do not confute authentic Prophetic traditions such as that in which the Prophet (peace and blessings be upon him) told his Companions about the dead whom he ordered to be buried in the well of Qulaib after the battle of Badr. Addressing his Companions, he said, "You do not hear what I say more distinctly than they [the dead] do." Likewise, the Qur`anic verse cannot be used to refute the established words of the Prophet (peace and blessings be upon him) who said that the dead can hear "the shuffling of feet as they [visitors of graves] walk away."

It is possible to give a different interpretation to the previously mentioned words of God from the chapter of “Fatir” and His words from the eightieth verse of the chapter of “An-Naml”, "Indeed, you will not make the dead hear" than that maintained by those who claim that the dead cannot hear the living. Based on this, the verses mean that God informs his Prophet (peace and blessings be upon him) that he cannot make the dead hear through his own power and ability; rather it is Him, the Creator of hearing, Who enables them to hear. This is similar to God’s words, "And you cannot guide the blind away from their error" [27: 81]. This means that success and guidance are in the hands of none other but God. He makes it clear that His Prophet (peace and blessings be upon him) is unable to make the dead hear except through His will; the Prophet (peace and blessings be upon him) cannot guide people to truth except by the will of God; he is only a Warner sent to convey God’s message.