No, you cannot. Both the Augury and the Djinn impose an alternative cost of "without paying the mana cost", and you have to cast the spell with that cost or not at all when using their effects. Overload is also an alternative cost, and the rules say, that you can only cast a spell via one alternative cost. The choice of which one has been taken by both cards.
118.9 Some spells have alternative costs. An alternative cost is a cost listed in a spell’s text, or applied to it from another effect, that its controller may pay rather than paying the spell’s mana cost. Alternative costs are usually phrased, “You may [action] rather than pay [this object’s] mana cost,” or “You may cast [this object] without paying its mana cost.” Note that some alternative costs are listed in keywords; see rule 702.
118.9a Only one alternative cost can be applied to any one spell as it’s being cast. The controller of the spell announces their intentions to pay that cost as described in rule 601.2b.
702.95a Overload is a keyword that represents two static abilities that function while the spell with overload is on the stack. Overload [cost] means “You may choose to pay [cost] rather than pay this spell’s mana cost” and “If you chose to pay this spell’s overload cost, change its text by replacing all instances of the word ‘target’ with the word ‘each.’” Casting a spell using its overload ability follows the rules for paying alternative costs in rules 601.2b and 601.2f–h.
If you cast a card “without paying its mana cost,” you can’t choose to cast it for any alternative costs, such as evoke costs. You can, however, pay additional costs. If the card has any mandatory additional costs, such as that of Tormenting Voice, those must be paid to cast the card.
(2018-07-13)
If you cast a spell “without paying its mana cost,” you can’t choose to cast it for any alternative costs. You can, however, pay additional costs, such as kicker costs. If the card has any mandatory additional costs, such as that of Tormenting Voice, those must be paid to cast the card.
(2018-07-13)
Does it work the same way if it's one top of my deck and i trigger Djinn of Wishes?
Former Rules Advisor
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(The Gamers: Dorkness Rising)
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Overload is an alternative cost. When you cast a spell "without paying its mana cost", you can't cast it for an alternative cost.
Ruling from Augury:
If you cast a card “without paying its mana cost,” you can’t choose to cast it for any alternative costs, such as evoke costs. You can, however, pay additional costs. If the card has any mandatory additional costs, such as that of Tormenting Voice, those must be paid to cast the card.
(2018-07-13)
Ruling from the Djinn:
If you cast a spell “without paying its mana cost,” you can’t choose to cast it for any alternative costs. You can, however, pay additional costs, such as kicker costs. If the card has any mandatory additional costs, such as that of Tormenting Voice, those must be paid to cast the card.
(2018-07-13)