I have an acne like bump on my head that appears to heal and thrn return as a hard bump a few weeks?

Possible skin cancer. This healing and recurrence pattern is typical of a minor skin cancer and you should have the area checked by your family doc, dermatologist or plastic surgeon.
See below. It is possible that you have a cyst, acne scarring, abscess, or another type of skin problem. If the bump grows, does not show signs of resolving, bleeds, or exhibits new symptoms... See a dermatologist for evaluation & suggested treatments. In the interim, do not pick or manipulate the bump.