Cast and location problems

I have had many problems with my cast as some have become unavailable during the course of filming. Will Meredith was originally going to play the detective however we have had scheduling problems due to his job. I have replaced him with Mike who was originally going to play a gang member.  I was going to film in my friends office for the detectives office as the mise en scene was suitable for my film as she had a large desk, blinded windows and enough space for the cast. I wasn't able to use this so I changed to the upstairs of one of my takeaways as there is a flat above and one of the rooms had the mise en scene that I needed.