Very bad service & charging stories all the time

This is the worst company to deal with. I had an account which was handed over to them with a settlement offer. They contacted me & I negotiated a settlement offer. They couldn't agree on the spot so they said they will get back to me which took them a very long while. Finally I got an SMS with a revised settlement offer. When they contacted me again I asked for banking details to make the transfer which they provided but the lady on the phone was reluctant to give me as she wanted me to rather do a monthly arrangement which I can't since I'm not permanently employed.

Now seeing that I have the banking details & ready to pay, she calls me again to say the settlement amount is too low & it can't be so. She can't allow me to settle, I would rather make a monthly arrangement & even threatens me with escalating the call to her manager. I told her what she is saying is nonsense as I have prove in my phone of the several settlement offer which is valid until the end of the month.