Working in the Islamic section of a bank even though there is mixing
Question

                I used to work in a bank for long time, in a very respected position. Then Allah guided me, so I moved to the Islamic department in the bank. During the last three years the bank started to employee women without strict conditions. I have denounced this for two years. which made them take some superficial procedures. Then I wrote my resignation letter and mentioned that the reason of me resigning is employing women widely without strict conditions. Then I got a job in a public company. I was offered -all praise be to Allah- half as much as my salary was in the bank. A year after this I found out that the environment of this work is full of hypocrisy, backbiting and sectarianism. In addition to this, I have increasing financial responsibilities that are starting to worry me. I have been offered to return to my previous job in the bank in the same position. 

My question is: 

Shall I return to my previous job in the bank? Bearing in mind that the bank is not abiding by Islamic laws completely. Only the administration follows them. The companies and the exchequer deal in Riba (interest). Now the bank also has increased the employment women in the administration.
Praise be to Allah.
    Your leaving the bank because of what you mentioned of them 
    employing more women without any strict conditions and your agreeing to work 
    for half of your salary, is indicative of goodness and success for you. If a 
    person gives up something for the sake of Allaah, Allaah will compensate him 
    with something better than it, and if a person fears Allaah, He will grant 
    him provision from (sources) he could never imagine. One halaal dirham is 
    better than a hundred dirhams from haraam sources. No body is nourished on 
    haraam things but the Fire is more fitting for it, as the Prophet SAWS 
    (peace and blessings of Allaah be upon him) said. 

    Secondly: 

    If the matter is as you describe, that the bank is not 
    abiding by Islamic laws completely, and they only follow sharee’ah when 
    dealing with individuals, but when dealing with companies and the exchequer, 
    they deal in riba, then it is not permissible for you to work in areas that 
    are not abiding by Islamic laws completely, and it is not permissible for 
    you to work in any way that helps and supports riba. 

    Similarly, it is not permissible to work in a place where men 
    and women mix, because of the serious evils that result from mixing. This 
    has been discussed in the answer to question no.
    50398. 

    What you have mentioned about the environment in which you 
    work now being a bad environment filled with backbiting, hypocrisy and 
    factionalism is something that can be overcome by working hard, offering 
    sincere advice and calling people to goodness. 

    If it is possible for you to work in the bank far away from 
    riba and mixing, then there is nothing wrong with you going back there, 
    otherwise be patient and seek reward, and have great hope for that which is 
    with Allaah. 

    We ask Allaah to guide us and you. 

    And Allaah knows best.