Alleged Contradictions in the Qur'an answer
How the Disbelievers will recieve their record on Judgement Day
How do we receive the record on Judgment Day? On Judgement day the lost people are given the Record (of their bad deeds): Behind their back [84:10], or in their left hand [69:25].

Verses in question:
69:25-31 And he that will be given his Record in his left hand, will say: "Ah! Would that my Record had not been given to me! And that I had never realised how my account (stood)! Ah! Would that (Death) had made an end of me! Of no profit to me has been my wealth! My power has perished from me!"...
(The stern command will say): "Seize ye him, and bind ye him, And burn ye him in the Blazing Fire."

84:10-12 But he who is given his Record behind his back Soon will he cry for perdition, And he will enter a Blazing Fire.

1. It is strange how such verses can be considered contradictory at all! Is it not possible for someone to recieve their record in both their left hand and behind their back at the same time? Indeed, this is what all the scholars of Tafsir have mentioned about these verses. Imaam Ibn Kathir Ad-Damishqi (d. 1372CE) explains in his renowned Tafsir Al-Qur'an Al-Azim:
(But whosoever is given his Record behind his back,) meaning, he will be given his Book in his left hand, behind his back, while his hand is bent behind him. (Tafsir Ibn Kathir, Abridged, Darussalam Publishers & Distributors, 2000, vol. 10, p.417 )
Similarly, Abul 'Ala Maududi (d.1979CE) writes about verse 84:10 in his prominent Tafheem Al-Qur'an:
In Surah Al-Haaqqah (v.25), it was said that his conduct-book will be given to him in his left hand, but here it is "behind his back". This will probably be for the reason that in order to avoid the humiliation of recieving the conduct-book in the left hand, in front of mankind, he will withdraw his hand behind and so recieve the conduct book "behind his back". (Maududi, The Holy Qur'an Translation and Brief Notes with Text, Islamic Publications (Pvt.) Ltd., 1991, p. 1018)
Syed Qutb (d. 1966CE), a revolutionary Muslim writer, gives the same explanation as well in his commentary, Fi Dhilalil Qur'an:
The Qur'an usually makes a distinction between receiving the book with one's right hand or left hand. Here we have a new image: the book is given from behind the back. There is no reason to prevent the combination of anyone being given the book in his left hand and from behind his back at the same time. It is an image of one who feels great shame and hates to be confronted with what he has done. We have no real knowledge of the nature of this book or how it is given in one's right or left hand or behind one's back. But we comprehend from the first expression the reality of escape, and from the second the reality of doom.
The above commentary should make it obvious that this allegation does not even approach a contradiction.

2. Even for the sake of argument, we assume that it is contradictory to recieve something in one's left hand and behind the back, there are still other explanations. Why must both verses be referring to the same group? it is entirely possible that they are not referring to the same group of "doomed people". Also, one may give a metaphorical explanation as Muhammad Asad states:
But as for him whose record shall be given to him behind his back;*
* At first glance, this seems to contrast with 69:25, where it is stated that the record of the unrighteous "shall be placed in his left hand". In reality, however; the present formulation alludes to the sinner's horror at his record, and his wish that he had never been shown it (69:25-26): in other words, his not wanting to see it is symbolized by its appearance "behind his back". (Asad, Message of the Qur'an, The Book Foundation 2003)
Indeed, this is plausible for human beings do not even know the nature of these records they will be given on the day of judgement. Will they be physical codices or scrolls? Or will they be in a different form, foreign to the human mind? If it is the latter, then we do not know what it means to "recieve" such a record in one's hands because we do not know how one would hold it.