Unprofessional consultant

The unprofessional service that I received today was horrible....So I short paid my rent for June(I paid on the 1st of July 60% of my rent), and they send me a letter of demand on the 2nd of July, of which I made arrangement to pay for the 7th of July. Today I receive a watsup message saying "the owner is saying they must proceed with legal action". Then I questioned this legal action since it was the 6th today not 7 working days as their letter state. The RUDE debt collector told me to refrain from messaging as their acting on behalf of the owner....My question is, when they sent me a letter of demand stating that I have 7 working days to make a payment were they not acting on behalf of the OWNER..heee? The level of unprofessionalism is too high.