Can I use Upserts to exchange an association completely when updating the parent (one to many)

I have a patient-complaints structure.
A patient has many complaints.
The patient has an unique index name.

When I supply the patient-name and a list of complaints, I would like the upsert to exchange the old complaints with the new complaints (deleting the old ones)

I did:

def save(params) do
    cs = Patient.changeset(%Patient{}, params)
    Repo.insert(cs, on_conflict: :replace_all_except_primary_key, conflict_target: :name)

def changeset(patient, attrs) do
    |> cast(attrs, [:name])
    |> validate_required([:name])
    |> validate_length(:name, min: 1)
    |> unique_constraint(:name)
    |> cast_assoc(:complaints, with: &BasicPatientInfo.Complaint.changeset/2)

def changeset(complaint, attrs) do
    |> cast(attrs, [:complaint_uuid])
    |> validate_required([:complaint_uuid])
    |> validate_length(:complaint_uuid, is: 36)

Unfortunately, this keeps the old complaints and adds the new ones.

Is there a way to let ecto replace the complaints?