Threatening not willing to accept arrangement but they want their money back

I took a loan through makanda and they work with debi check. Their system gave them issues and the Debi check never went through. I ahve explained that i have not budgeted for the full amount and that i will eft R500.00 at month end but the lady chatting on their watsapp group is refusing to accept the arrangement threatning me with field agents coming to my workplace that i have to pay R550.00 for and Emolument not willing to accept any agreement what so ever. They are Rude and disrespectful to their clients and accusing people of not wanting to pay but i am trying to advise that i will pay via eft but dont have the full amount