STOP threatening and change payments and dates from YOUR side!! It is unfair practice

I am sick and tired to receive your emails with the same old story - Your client is no longer accepting my monthly arrangement - Notwithstanding the fact that I tripled my monthly payment over the last six months, that you pushed my payment date from the 30th to the 20th of a month (without consultation - YOU decided that is the new payment date). I requested a final settlement as I am so close to finish a 12 year nightmare with GLA and although you send me confirmation of 50 to 70% discount, you calculated that I must pay R 2450 to settle a R 3500 amount - according to you, THAT is 50% discount. For the best of 12 years I had a workable relationship but since you appointed a new person around 4-6 months ago, my life changed into a nightmare