The CAA will not grant an exemption. Its the responsibility of the candidate that they understand their own licence its revalidation requirements. This includes the correct selection of an Instructor.
If its expired its expired and you will need to meet the requirements to renew it. Less than 3 months expired it will be no required training plus an LPC. Any EASA examiner can do the LPC for you.
If you rating has expired you can't fly.