Am I british by Descent or Otherwise than by Descent

[Shazzzzy72]

My father was born in st.lucia.migrated to Uk in 1962.Finished secondary school in 1964.Was recruited into the Royal Airforce in 1964 at age of 17.married my mother in 1969 in north london which was their usual place of residence.My father was a british subject.I was born in 1972 in Germany while he was posted there 1970 to 1976.
Now the HO have continually said I am british by descent and I do not agree as my father was a crown servant designated to work in Germany.If he wasnt stationed there i would be born in the UK.And with the documents Chapter 20 and Automatic acquisition of british citizenship states in general that a person born outside of the UK before 1983 to a parent on crown service which was designated and as long as they were recruited in the UK is not british by descent but otherwise than by descent.This has ruined my life.Ave had deportation orders against me 3 times.i have 21yr old and 14yr born here who have no status because of that.
The effect was that as I was born while dad was a british subject in 1972 i was british by descent at birth.in 1978 st.lucia became independent and so therefore Daddy became a st.lucian citizen so i lost my status.My father never returned to st.lucia and always had ILR and ILE over the ensuing 40plus years..My case has just been made complicated and messed up.Please give me some guidance.
My case has been in the media