I had enough sciences completed at my first institution to earn a BS but I was granted a BA. I never ever list my degree to be a BS.
When I become a Registered Nurse I will have MBA, BA, ADN. When I graduate the RN-BSN I will then be a MBA, BA, BSN. And when I finish my doctorate I will be a PhD, MBA, BA, BSN.
I agree with the poster that said you should NEVER add something that is not true to your resume. It is not enough to say that you did not know or that you did not think it mattered. Listing credentials or fudging your education/degrees in any way is grounds an employer can use to terminate your employment.
Besides, I know two nurses with BS (not BSN) as credentials. They do not add the "N" because their school did not give them that degree. They earned a BS. I do not think they have trouble finding jobs. The two I know hold managerial positions and have done so for some time. Good luck.