(a) If the plaintiff does not, within the time allowed for acceptance of the offer of compromise and before the commencement of the trial, file the plaintiff's notice of acceptance, the offer shall be deemed to be withdrawn and shall not be given in evidence.
(b) Unless the plaintiff recovers more than the sum specified in the offer of compromise, with interest from its date, the plaintiff shall recover no costs accruing after the plaintiff received notice of the filing of such offer, but shall pay the defendant's costs accruing after the plaintiff received notice. Such costs may include reasonable attorney's fees in an amount not to exceed three hundred fifty dollars.
(c) This section shall not be interpreted to abrogate the contractual rights of any party concerning the recovery of attorney's fees in accordance with the provisions of any written contract between the parties to the action. The provisions of this section shall not apply to cases in which nominal damages have been assessed upon a hearing after a default or after a demurrer has been overruled.