windows issue

My computer is a few years old. About two months ago I took it in for repair. I have a windows 8 but when I collected my computer back it is now running windows 7. I questioned it but was told it would run better. After months went by I began to have issues. Windows now tells me that I am a victim of software counterfeting. The techie at the store replaced my windows 8 to seven and now the computer has shut down my social media etc. My word and Photoshop was even replaced by another version. The store has sinse moved and I rely of my computer for work.Where should I take it.