Bad Service from Just Letting, Stellenbosch

We are currently renting a flat in Stellenbosch for my daughter through Just Letting. With the entry inspection we noted that there is mildew on the bathroom ceiling and in the kitchen cupboards and that the intercom is not working. Despite numerous emails and telephone conversations with the principal and owner of the the branch, nothing was done about the situation. Today I received an email notifying me that our rent will be increased with 19% for the next lease year. We are currently paying R4600 for a bachelor flat, with the increase we will be paying R5500 per month. That is the same amount of rent another tenant in the same complex with 2 bedrooms are paying.