I was charged 138$ for my tax return when I filled a free return is there a reason why this would be

I just experienced this myself. In addition, to the Turbotax Product, and other offerings, there is an additional fee of $39 for electronic filing. It is clearly spelled out and you had to of clicked (accepted) this fee. Or you could have used snail mail. Fair or not, I paid and have moved on. 

There is no fee to efile or go get Direct Deposit.  If you paid the extra 39.99 Refund Processing Service charge (44.99 in California) that was an extra service to have the fees deducted from your federal refund.  You could have paid the fees upfront with a credit card to avoid the extra 39.99 charge.

But this does still not answer the original question.

 Could it be for a tax due?

How to review your fees https://ttlc.intuit.com/replies/4202093 

Why do you think it was supposed to be a “free” return?