Being held ransom

I am in the unfortunate position to have a home loan with SA Homeloans. This is the biggest mistake of my life and I would not recommend any person to switch/take out s bond with them without being fully aware of the poor service offering they have. I have a problem with water seeping through my walls which is structural. SA Homeloans tells me that they do not cover this in their HoC. They will also not allow me to take out insurance with another company that covers more than they do for less unless I cede the policy to them. Why should I do this? These guys are modern day ****** and now I am unfortunately stuck with them.