Causes trouble at work place

I resigned from my work as we are immegrating. I am currently awaiting my payout upon which i indicated to Makanda Finance that i will settle the outstanding amount. This was agreed upon via email on 5 November 2019 that i would pay the balance on 17 November 2019. So today i receive a phone call from a close friend who is still employed at the company i recently left and he indicated that Makanda Finance sent a debt collector with a letter with ALL my personal information on it !! He then took possession there of before and sent me photos of this. Now the lady at Makanda whom i have arrangements with is ignoring me and this after i said i am not working there anymore and they should call me on my cell or home. I am utterly disgusted in this! The fact that they just don't give a f!@% for arrangements made !! I called my attorney and was adviced to institute a claim for damages as this damaged my name extremely badly!!! It placed me in a bad light although arrangements were made! Clearly Makanda does not know the law as no-one is allowed to contact you at your place of employment for any debt, never mind show up! People PLEASE DON'T, PLEASE do NOT do business with this company!!! They cause so much trouble and they don't stick to arrangements!