Forster & Garbus LLP Debt Collection Complaint

Forster & Garbus LLP Debt collection department,

Credit card Communication tactics Threatened to take legal action New York

I have a settlement Stipulation in which I pay $100.00 on or before - of each month until the settlement amount is paid in full. So far I have send in - payments certified mail on time. Twice now have I had them cross out the account number for which the payment was made on and replaced with a different account number followed by a letter to me stating that I am in default of the stipulation of settlement and they plan on applying judgement against me. I believe this is a dishonest way to collect on - different accounts and to manipulate me into paying the settlement in full.