My husband and I sold our house and moved from XXXX to XXXX in XX/XX/XXXX. I was hit with a big bill from XXXX XXXX for {$580.00} in 4 mos. I paid it off by a personal check on XX/XX/XXXX. XXXX XXXX, my ex-utility company, continues to send off debt collectors in spite of my many attempts of phone calls and mail correspondences to stop such harassment. 
Would you please advise? I thank you so much in advance.