Poor service from NHBRC Gauteng

NHBRC was doing some remedial work at my house from October last year and it was supposed to be done in 4 months, by the end of February 2021 and till today they are not done. I fail to get responses to the emails I send them. They don't communicate with me unless I send them an email or call. Most of the time they don't respond or when they do they would promise to call me back. This is the 10th month since they started and they are still not done. When they started they gave me rental for 4 months. Now I am paying for the bond which they are fixing, the rental and storage.