a mess of an investment!

I have been trying to locate my funds from a Discovery Provident Fund since January. I resigned from my employer in December last year. From August our Provident Fund provider was Discovery. So on resignation I opened a Preserver Fund with Discovery. I was taken from pillar to post since then trying to get the funds (external) into the Preserver account. Then I was told that great the funds will be coming in and those funds together with the funds from Discovery itself will then be put into the Preserver because we cannot make adhoc investments into it. Fast forward to when the funds then came in, Discovery decides to only invest the external funds into the preserver and not the ones from their own fund (yet those funds had already been withdrawn as I had signed forms for that withdrawal to go into the Preserver). Since then I have been struggling to get clarity from Discovery as to why both funds were not investment at the same time and where are the funds from their own fund? I gave instructions to invest both into the Preserver, why was this not done this way and if this changed, why was I not informed and told where those funds would then be. I am constantly calling and sending emails that do not get answered. Should I just withdraw all my funds and use a different provider because I do not trust that you can handle my investment.