Can a F-1 visa student gain a residency status?

as you were clearly told by the consulate ...student visa are non immigrant visas.. you do the course and go home there is no path to a green card

Of course not. Student visas are non immigration non residence visas.

You are on a student visa, you cannot gain residency for tuition purposes. Even though you may be living in Iowa, you still have to pay international student tuition costs. If you are referring to legal residency for the US, a student visa does not lead to legal residency in the US. When your classes are done, you go home.

As an international student you never will be a resident. Even for an US citizen to claim residency for tuition purposes in a state the only way is to have lived the required time in that state (usually a year, but it can be longer). There is no way you can become a resident for tuition purposes in Iowa or any other state. You can change universities, make sure you understand the process to do this correctly. Discuss this with your international student adviser.

I don't think that international students can be a "resident" of a certain state in order to get a lower tuition rate (sorry about the bad news if that was the point of you waiting to do this). Your non-immigrant international student visa is an arrangement between you, the college that you attend, and immigration. As far as I know, international students always pay triple tuition no matter what college they attend and no matter which state they live in.