If the violation has not been corrected pursuant to the requirements set forth in the notice of violation or, in the event of an appeal, within the time set forth in the decision of the municipal authority upholding the decision of the City, then representatives of the City shall enter upon the subject private property and are authorized to take any and all measures necessary to abate the violation and/or restore the property. It is unlawful for any person, owner, agent, or person in possession of any premises to refuse to allow the City or designated contractor to enter upon the premises for the purposes set forth above. Within thirty days after abatement of the violation, the owner of the property will be notified of the cost of the abatement, including administrative costs. The property owner may file a written protest objecting to the amount of the assessment within 15 days. If the amount due is not paid within a timely manner as determined by the decision of the municipal authority, the charges shall become a special assessment against the property and shall constitute a lien on the property for the amount of the assessment.