unhappy client and unprofessionalism of this company

I have never see such an *********** law firm in my life.....I called following up regarding my account and how to settle it it took me about a week to get to the relevant people to assist me however they still call me on that process to please pay, just when I got things right made arrangements to pay I still receive calls at 7;05 in the morning, in the afternoon after working hours around 6:30 in the evening even on public holiday just when I have escalated the matter I get email again saying I didn't honor my promise that time it is written in black and white via email that payment will be due not later than 30th of September I'm so disappointed for such a law firm to operate in such unprofessional manner. why should I help and assist them on how to handle their matter by have to explain my self to 5 different people in 1 day the same process what kind of system are they using, I did follow up calls, and email everyday this month. even after all the trouble they still make an arrangement without me something that I didn't even signed up for.