The violation of any material portion of this franchise by the Company or its successors or assigns, or its failure to promptly perform any of the provisions of this franchise, shall be cause for forfeiture of this franchise and the termination of all rights under this franchise. Such forfeiture shall be accomplished after written notice to the Company by the City, and a continuation of the violation, failure, or default specified in the notice, for at least sixty (60) days from the date the notice was served upon the Company. If either party determines that there is a default under this franchise, the other party shall be given a written notice describing the default, stating whether a forfeiture or termination of the franchise will be sought, and where the default is curable, providing a reasonable time to cure the default, which shall be not less than thirty (30) or more than one hundred eighty (180) days.