Business and Dealings

Working for a company that prepares software for banks

Q: I am a software engineer, currently working in a software house, I wanted to switch my job and later on I got a job in a very nice & reputable company. But they worked for banks, basically they are a banking solution provider, I know this thing from the very first day, but due to the lack of my knowledge, I was assuming that working in banks is impermissible and as I will not be going to work in a bank that's why I didn't bother. But when I got the offer letter, I did Istakhara. I did not see anything in my dream or I didn't get the clear picture of what I should do, then I searched on the Internet that what Islam says regarding this issue. I've found in many places that its forbidden to work
for bank or work for such companies who gain their profits from banks, so I refused.

I wanted to know that is it allowed in Islam to work for such companies that help banks? Keeping this in mind that I didn't know at the time of refusal that what kind of software they were requiring me to make.

Selling a property

Q: My mother bought a property with a share from her brother. The price of the property has doubled and now I want to sell the property. Should I give him the same amount of money he invested at that time or do I give him profit? Because the price of the house has doubled. There was no price agreed on at the time.

Mobile recharge in exchange of using a website to send SMS

Q: An Indian website is giving money as mobile recharge in exchange of using that website to send SMS in India. We have to sign up on the website and become a member. When a member sends an SMS to any contact number, he gets 2 paisa. Like this, the more one sends SMS, the more money one earns. We can send only 50 SMS per day, means we can earn only 1 rupee as mobile recharge. When a member has earned 10 rupees at least, the he becomes able to recharge his mobile SIM Card. The member can send this money to any mobile number via website. I used this website and made two accounts with different mobile numbers. Now I send 50 SMS from my one accounts to another and earn money as mobile recharge. Please tell me if my earnings are Halal? Is using this website Haram? Or if there is any condition to use such website for earning money, then describe please. 

Cash prize draw as an incentive to complete a survey

Q: To encourage consumers to fill out a survey, we offered entry into a cash prize draw as an incentive if you complete the survey. 5 respondents will each win a certain amount of money. After capturing the respondents details, my systems crashed and I lost all the data, I tried everything I could and there is no way of retrieving that data. What do I do ? I have no way of knowing who completed the survey, so how do I choose five winners. Is this form of incentive permissible?