Surrey Police Department interview questions

I completed and submitted the lengthy application online on the 6th December 2016. After a long wait I got an email to attend an interview and Microsoft Excel exam on the 31st January 2017. I was successful in getting the job and I was told it would take up to three months for the Security vetting to go through. So I stop looking for jobs as I got the perfect one On the 9th March 2017 I received an email stating that they couldn't offer me the job due to unforeseen circumstances. So I was gutted as I had just wasted three months waiting for a job that they took away over an email. The job offer had conditional which I had to pass the security vetting, medical and references.. But as the conditions weren't met as the job was retracted before I got there. I did nothing wrong but wait for a job I successfully got. Please be careful when a job offer has conditions attached.