Done paying now have to bargain for my paid up letter 😡😡

Good day Can I kindly be assisted with my paid up letter as they have debited 1863,83 from my account yet no paid up letter . They are the ones now who are a stumbling block because I cant get my certificate clearance.it seems this collection companies when you get into an agreement with them and they get their money they no longer assist, you now have to beg them to send the letters Why do we have to bargain to get such help from them,its frustrating really 😡😡