Repo rate decrease but my bond is increasing.

I have a bond with Standard Bank and I was excited that the Repo rate was going down by 25 based points which would ease up my household budget, I got the shock of my life when I received a letter from them saying that my bond was increasing even after the RB announced the decrease of the repo rate. I called the call centre to get an explanation and no agent can explain what the cause of the increase was, I requested to speak to a manager and till today no one has called me to assist with my query. Its been two weeks now waiting for their call.