To answer the question, yes, an elderly person who is not declared legally incompetent absolutely has the right to determine what type of care she receives. She has the right to accept and to refuse care, even if the refusal of care is to her detriment.
Unfortunately, your explanation does not really tell us what happened. Please provide additional details as to what happened so that you can get better guidance.
Unless you came into my office, signed a contract and wrote me a check, I am not your attorney, and you are not my client. This is not intended as legal advice and should only be used for informational purposes only. You should never believe any information that you receive on the internet, especially information that is probably being provided in the late evening hours when I should be sleeping.
As long as you are able to state your wishes and have not been determined to be incapacitated, your medical providers should follow your wishes. If, however, their medical opinion is that your requests are not appropriate or medically feasible, they may not. As long as you remain able to make your own decisions, you are free to seek another provider.
While I agree with the others who tried to answer your question, it also depends on what you are relying on to pay for your health care needs because not every program provides the same benefits. In addition, depending on your medical/health condition, the hospital may not have the capability to properly care for you, and the MDs may have only limited options in terms of how to treat you.