I've been using Bio Oil for markings and general discolouration on my body. I've been using it for 2 years and it's not a miracle product. My skin has improved significantly over time, but you are not really giving it a chance, a week really isn't enough time to see any improvement.
Scar tissue is permanant damage, no matter what you do or use, it will never be the same as your normal skin again, you can just hope to improve on the appearance.
If you have Keloid scarring, which is usually raised and red, you may find using a product called Cica Gel more effective. It is a sheet of silicon, which helps to rehydrate and flatten raised scarring, so the appearance is greatly improved. But again it will take time.