unlawly detained by city property - locked in.

I have a huge problem with the manner in which City Property treats its tenants. I am currently renting an apartment for 5300.00 a month which does not include electricity and water and municipal charges. The flat is a two bedroom flat in Pretoria (Scorpus heights). This month i short paid with 900.00 only and on the 11th of the same month they came and locked my wife while she was in the flat. Prior to that I called and made arrangement to pay the balance later. They allowed me to pay R500.00 in the meantime and then the balance of R400.00 at the end of the month with the rental. I informed my wife of the situation and asked that she go make a direct deposit at the bank. When she tried leaving she found that she was locked inside the flat by City Property. Firstly locking in or out a tenant is ********, even worse when locked in because that is tantamount to being detained or arrested. ******** arrest may be a subject of a civil suit in the form of ******** arrest and detainment. The Service is really bad.