Just ignore what they write... cos that time it happen to me also and i ask the SA and he say they treat it as they using mineral oil but can come back after 10k for next servicing so dun be too concern over that piece of paper...
jz to check, if in paper written mineral oil and next service is next 5k but actual should 10k.
if unlucky after 5k and before 10k, ur engine give u problem, will tcm push the blame for not following servicing schdule?