Parents asking me to be a reference on their foster application

I'm having a dilemna. My foster/adoptive parents are asking me to be a reference for their foster application. They gave their CPS social worker my name, number, and email address. Their social worker has since emailed me an Adult Child Reference Letter to complete. Here is the problem: My parents and I are not on speaking terms since over a year ago, when I got seriously ill. At the time I became ill, I told my parents about my illness, but they told me it was all in my head and I needed to see a counselor. I believe they got to that conclusion, because as a teen I suffered from anxiety and depression and often complained of physical symptoms. I think they're assuming I'm just depressed/anxious based off that experience, and have discounted the fact that I could ever actually get sick. I tried to talk to them about my illness a few times in the past year to year and a half, but every time my parents have blown me off or acted as if I'm a silly child. I am in my twenties now, completely independent of them for many years now, and feel very insulted by this treatment from them. I even have blood work, labs, a letter, and confirmation from both my doctors that I do, in fact, have a serious chronic illness still. Despite me telling them about the blood work confirmation from my doctors, they still refuse to acknowledge I'm sick. I have literally had to go through the past 14+ months emotionally, financially, and physically alone, with the exception of my partner, who has cared for me while I've been sick. The complete lack of emotional support or even ACKNOWLEDGEMENT of my illness at all, has been devastating for me emotionally. That being said, my relationship growing up with my adoptive parents was not great either. My mom was emotionally abusive (in not so obvious ways, so it was confusing), emotionally distant, strict, gave special treatment to the other children in front of me, and not nurturting to me. Being a child from a traumatic situation, I therefore did not get the comfort or compassion I needed to recover, and was actually harmed a lot more emotionally. My adoptive dad let my mom do most of the parenting and discipling, was pretty reserved in nature, and did not give me affection really. I never felt close to either of them. The idea of even visiting them fills me with a huge amount of anxiety and stress. My body physically gets tense even thinking about it. Yes, I have tried many times to talk to them about what bothers me in this dynamic, since I was young, but they just do not respond well. Nothing changes, things are laughed off, or my mom tells me "You want me to be something/someone I'm not." They listen but things don't change, and I am still treated as if I'm incompetent. In conclusion, it seems as if they are delusional in asking me to be a reference, when we don't have a good relationship and I have not even seen them in a year, never visit, and don't talk to them. I cannot give them a good reference, but if I don't respond to the social workers calls or emails, then CPS will probably assume that there is a problem anyway, since a child of their applicant isn't getting in touch with them. I'm sure my non-adopted sisters will give great reviews of my parents, but I can't, and I won't lie. My parents abandoned me in during a major health crisis, and I'll never forget that. Regardless, I feel like I've been put into a really bad position- because if I don't respond to the social worker, they will think there is a problem, but if I do respond, I will probably have to deal with my parents being ticked off that they don't get approved. Maybe a child with a different personality would do much better with them, but if not, then I don't want another kid to end up suffering like I did. I am still in counseling for issues I have with them. I'd also like to add-my physical needs were completely provided for while living there, but the emotional abuse was the problem. So what would you do? -Continue to ignore texts from my parents, and calls from the social worker -Talk to the social worker and explain my whole experience (My parents will probably not be approved to foster) -Tell my parents I can't give them a good review and that I will not speak with the social worker -Or something else Please let me know what you think. I have to figure out how I want to respond soon (if at all), because the social worker has already tried to contact me twice). Thank you for taking the time to read and respond!