Complain directly to the landlord
If your landlord has a complaint handling channel, you can use this channel to make a complaint. For example, some formal housing agencies will have departments and personnel specializing in handling complaints. You can call and ask, or find the corresponding information on the intermediary website. If your landlord has no complaint handling channel, or you don't know where to complain, it is reasonable to say that the tenant needs to make a written complaint, write down all the matters you want to complain about, and then let the landlord investigate and ask. Similarly, they also need to reply to your results and handling methods in writing. If you are not satisfied with their reply, or your landlord doesn't reply to your complaint, you need to find an alternative dispute resolution (ADR) to lodge a complaint or sue. Special reminder: ADR only handles all kinds of complaints in England. Please refer to the Scottish Shelter.