Account closed but still receiving billing

My son received an invoice number ***1 dated 01.07.2023 to 31.07.2023. It been almost 6 to 7 months. My son it not using this company. Last time there was somebody from Rain who called him even provided him the correct invoice to make a payment for last year which was outstanding and he paid.which the service from that gentleman was excellent he called my so and my self. Now today we received this invoice let me tell you somebody is not doing what he/she supposed to do. And which is not the right way because now the company will look bad because just of the individual who is naughty. RAIN deal with this person and just not be happy of sending emails without checking. I will be happy if this can be solved urgently. Today Rain is looking bad from this platform because of your silly mistakes.