Dear Agapito
I was in Iran last 6 month ago and just want to tell you that's a nice country with nice people.
In Iran you aren't able to use your credit card, you can use only one local system named "Shetab"
I found a Financial company in Iran they could withdraw money from my VISA card and gave cash to me.
This is Iranicard and their URL is www.iranicard.com . They also provide MasterCard and VISA card.
They can transfer money for you to your family also.