The phrase "to have no complaints" means that a person is satisfied with a situation and does not have any negative issues or problems to address or express dissatisfaction about. Full definition
Q: If have a complaint about a REALTOR ® from another board can I file an ethics complaint? (scbr.org)
We normally do not have any complaints about support. (bellybandit.com)
Overall, I didn't have any complaints with display, it looks and feels good and is quite responsive which is what one needs in a budget smartphone. (firstpost.com)