Unfortunately there is no quick fix for your problem. Your boobs will grow at their own rate and no amount of massage or rubbing oil will effect that.
Truth is, your breasts will mature when you start your period. It is the estrogen (female hormone) that will encourage your breasts to grow. It is very technical so I will try to explain it the best I can.
When you approach your 'teenage years', the first outward signs of breast development will appear. When your ovaries start to release estrogen, fat will start to collect together, causing your breasts to enlarge. Usually, when this happens, you also get pubic hair and hair under your arms.
Once you start ovulation and menstruation begins (your period), your breasts will then mature connecting all the milk ducts, glands and lobules.
Development is different for every girl, in some girls it happens at a younger age than in others. Personally I did not develop until I was 14 and even now I do not have the largest breasts.
Try to remember that you will develop at the right speed for you, and they will grow to the right size to suit your body shape.
Please try to not worry about it - trust me, it will happen eventually!