One of my service providers is offering me an ISO 9001 calibration certificate, but I cannot find them on the EA site. Is this legal?

In theory, this should not be possible, because the logo of a system certifier cannot be applied to a product, and in this case, the certificate is considered as a product of the laboratory. This requirement is clearly defined in the accreditation standard for certifying organisations ISO/IEC 17021, paragraph 8.4. In this case, refer to your service provider’s certifying agency or the national accrediting agency.