First, I would call the contact number for the company that provides insurance for international students to confirm that you are not eligible. Maybe they will still provide insurance coverage for you and that would be the best option. Their phone number is listed to the right when you click on this link.
22-23_CalPoly_Snapshot.pdf (relationinsurance.com)
Second, you should still be able to purchase insurance through coveredcalifornia (coveredca.com) – you will just have to pay the full price rather than being eligibile for a financial discount because of family income. If you go this route, you should call Cal Poly SLO and see if they can tell you if you can use an HMO or if you should get a PPO plan (HMO = Health Maintenance Organization – it limits which doctors you can see and the ones you can see may not be available in San Luis Obispo. PPO = Preferred Provider Organization and it gives you more flexibility. Also ask them what their minimum insurance coverage requirements are. My kids’ schools had specific minimums we had to meet.
Third, you can also call Anthem Blue Cross – they are a major insurance provider. Tell them that you want to go to college in San Luis Obispo and what plans do they have for you.
Here is the contact information for anthem blue cross:
[833-932-1034 Mon-Fri, 7 a.m. to 7 p.m. PT
Good luck – and I hope someone here can help you with additional information. Also, please try to see if the college can give you any additional help or information. This seems odd that they aren’t able to help you.