Since you never received the money, it shouldn't be in your overall revenue if you are a cash-basis taxpayer. No additional adjustment is necessary aside from not showing the invoiced amount as income.
However, if you are an accrual-based taxpayer, and this income was reported in a prior tax year you may need to make an adjustment. Let us know if this is the case for you.
Sorry you can't. You can't deduct income you never received. You will just have less income to be taxed on. You take the loss by still deducting all your expenses but not your time or labor.
Since you never received the money, it shouldn't be in your overall revenue if you are a cash-basis taxpayer. No additional adjustment is necessary aside from not showing the invoiced amount as income.
However, if you are an accrual-based taxpayer, and this income was reported in a prior tax year you may need to make an adjustment. Let us know if this is the case for you.