According to China's Intellectual Property Law, an applicant can apply for an invention patent or a utility model patent at the same time for the same invention. Because the requirement of an invention patent is higher than that of a utility model patent, the patent office should not only conduct a written examination, but also conduct a substantive examination during the examination, so the utility model patent is generally obtained first, and the utility model patent is obtained if it meets the substantive requirements of the invention patent. Note: An invention can only obtain one patent, which can be a utility model patent or an invention patent.
You said that the invention was rejected and you could only apply for a patent for utility model. See if the utility model patent can be approved.
When the application for invention is rejected. Have you been asked to make corrections within the prescribed time limit? If so, you can resubmit within the specified time limit.
I suggest not to transfer it to an entrusting agency. It's too much trouble.