Select Portfolio Servicing review: Mortgage handling 1

On March 29, 2023 I sent in $37, 059.23 to Select Portfolio Servicing to be applied towards my monthly payments which would have covered a total of 12 months, since I already had a partial credit on my account. That means my next monthly payment would have been due on April 1, 2024. Since then I have had nothing but trouble. It began with a phone call from SPS Mortgage saying I was past due on my account for the May 1, 2023 payment. I let the representative know that the large payment was to be applied to my monthly payments, representative said okay and she would take care of it. Over the next several months I had several phone calls and letters saying I was past due. I had to continue explaining how the payment was to be applied to several representatives and managers since SPS Mortgage kept reporting me as past due. I was always reassured by Managers and representatives that this would be handled. When the calls continued and past due letters kept coming I finally requested my money back. SPS Mortgage stated they are unable to refund me my money nor can they apply the money towards my monthly payments and that I am now being reported to the credit reporting agencies as past due. I am also to resume my payments or my home will go into foreclosure! I didn't know what to do so I sent in 2 more payments in October of 2023 to cover the past due months and SPS Mortgage is now expecting me to make my next payment on November 1, 2023. My credit report is down by 50 points because of the past due reporting which is now affecting my other credit accounts and I cannot afford to keep making these double payments. SPS Mortgage didn't seem to care and let me know that if I don't then my home would be reporting as past due, continue getting late fees and added interest and go into foreclosure. Please Help!