Your first mistake was buying something when you were unsure of its origins.
We should also distance ourselves from matters dubious and doubtful.
The Prophet (sws) is reported to have said:
Leave what makes you doubt for things that do not make you doubt. (Tirmidhi, No: 2442)
Things legitimate and illegitimate are clearly defined in Islam and, in between them, are doubtful things, which should be avoided.
A striving Muslim businessman should be wary of the doubtful things in order to keep himself clear in regard to his faith and his honour because one who falls into doubtful matters is sure to fall into that which is unlawful (Haram). A tradition of the Prophet (sws) states:
A time will come upon the people when one will not care as to how he gets his money whether legally or illegally. (Bukhari, No: 1941)
The Prophet (sws) has also exhorted the believers to strictly adhere to truthfulness in business transactions. He says:
The seller and the buyer have the right to keep or return the goods as long as they have not parted or till they part; and if both the parties spoke the truth and described the defects and qualities [of the goods], then they would be blessed in their transaction, and if they told lies or hid something, then the blessings of their transaction would be lost. (Bukhari, No: 1937)
The tradition implies that Allah blesses business dealings if both the buyer and the seller are true to each other. Telling lies and hiding facts will result in the loss of divine blessing.
Almighty Allah has declared thievery unlawful and warned of severe punishment such as cutting the hand of the thief from the wrist joint if the necessary legal conditions for the award of punishment are met. Even if the thief escapes worldly punishment and gets away with stolen goods, it is not permissible for a Muslim to knowingly purchase or sell these items. The stolen items are neither to be bought nor sold by those who know the reality.
By buying stolen goods, we effectively condone the act of stealing and create the demand for stolen goods, and stealing.
Thus, purchasing stolen items after knowing their reality is not permitted. If one does so, he is one of the thieves. He has to return the items to their original owner; if he had sold them then he has to give back their price on the day of their sale to the owner. It is the same if one has used them up and the items no longer exist. Ahmad and Ibn Majah reported from Samurah that the Prophet (Sallallahu Alaihi wa Sallam) said:
“If belongings of someone are stolen or lost and thereafter he finds the same belongings with another person, he (the real owner) is more entitled to take them. In this case, the purchaser will take the price back from the seller."
If he does not know the owner and cannot pay him back his rights, then he should give the items in charity on behalf of the owner.
As for the price he has paid to the thief, he may take it back from him as stated in the Hadith. If he cannot find the thief, or cannot take that from him he has no right to take it from others.
Therefore, you have to return the item to the real owner or pay its price if you have used or damaged them.
If you do not know the owner, you have to spend that on needy and poor people. Do not re-sell the ipod. Give it away in charity and be wiser next time! JazakAllah