Bad treatment from Edgars after paying them

I used to have an account with edgars and i lost my job and defaulted on payments and was handed over. Once i got a job i paid the account on a monthly basis and all of a sudden they stopped debiting my account so i thought the account was paid up. after a while i was contacted y another debt collector from a different company for the account and i made arrangements to settle the account once off and they offered me a discount on the account to settle it. And now all of a sudden I am being abused by another debt collector threteniong legal action against me I am so dissapointed in them