(c) A repayment plan required by a landlord pursuant to (b)(i) of this subsection will be designed both to pay the past due bill by the following May 15th, or as soon as possible after May 15th if needed to maintain monthly payments that are no greater than six percent of the tenant's monthly income, and to pay for continued utility service. The plan may not require monthly payments in excess of six percent of the tenant's monthly income. A tenant may agree to pay a higher percentage during this period, but will not be in default unless payment during this period is less than six percent of the tenant's monthly income. If assistance payments are received by the tenant subsequent to implementation of the plan, the tenant shall contact the landlord to reformulate the plan;