Legal Question about Debt Collection and Interest?

Questioner

In April 2015 I made an arrangement with the collection agency against final settlement, the original amount was 6856.01, an amount of 5000 euros was agreed that I can pay over three years and that I do this every month as agreed, now I receive a letter that too much interest has been paid and that the corrected amount of 2,078.67 will be deducted, but not from the agreed 5,000, but from the original amount of 6,856.01. My question is this correct or should this be deducted from the 5000, -. After telephone consultation, it is shielded with repair costs. Is this correct?

Lawyer

This logic escapes me. Have you contacted the collection agency and asked what the reason is? If the parties have agreed that you will receive an amount of €5,000, it seems to me no more than logical that any excess interest is deducted from this agreed amount.