Threatening Messages, unprofessional

I fell behind with my Woolworths Personal Loan and Brooks and Luyt was assigned as the attorneys to in the money. According to records I have, I called them on: 28 Aug, 4 Sept, 11 Sept, 15 Sept and today, 24 Oct. On 4 Sept I've made an arrangement with them to pay back the money owed. BOTH parties were happy with the arrangement. It stated: I will pay my account off with payments of R1,000 at the end of each month. First payment went off on 29 Sept (proof available). According to the arrangement, next payment will be end of October (today is 24 Oct). I confirmed with Brooks that they only expect next payment on 1 Nov. I received threatening SMS'es on: 23 Oct and 24 Oct. If you look at the timeline, they were sent prematurely, as payment is only expected on 1 Nov. I cannot express my frustration on this page enough. These SM'es read: "URGENT MESSAGE: Payment to your Woolworths account is LONG overdue. Failure to make an IMMEDIATE Payment to this account will result in legal action being taken against you. From Brooks & Luyt Attorneys (011) ********** " and the most disturbing: "You have not honoured your agreement in paying your Woolworths account. Summons may be served on you by the Sheriff of the Court at your home or place of work. In order for us to withhold the process we request an immediate payment of R200 and a call back for a suitable arrangement. Brooks & Luyt Attorneys (011) ********** ". I need someone from Brooks to call me with a proper explanation. If there were ANY additional fees, penalties or charges raised to my account due to "late payment" or whatever reason, this needs to be addressed. I need a full statement on my agreement as well as the outstanding balance on this account. The helpful operator I spoke to today, told me he would take this up with his superior, and I thank him for that. He was not at fault, as he works at a company that does not have their processes in order. It is really, really frustrating to be made out as a ********, and where a Sheriff is assigned to take it further. As well as forcing you to pay R200 AND request a callback.... unacceptable.