This sign has been there for weeks. The sign is within Highway land as the wall is probably the boundary. The Freeholder of the land adjacent is probably Southwark Council, Estates Agents are a public nuisance and they don't control their installers. Where I live we do not permit such signs to be erected on our property.
Your report has been investigated by our team and this is not owned by Transport for London which means that we are not able to resolve the issue. Please contact the owner. Should you need anything else or have any questions please contact our customer services team on 0343 222 1234