I took out a bond with Standard Bank for R210,000

I took out a bond with Standard Bank for R210,000.00 more then 12 years ago. The bank valuated the house for R850,000.00, but they insist I take out structural insurance and life cover on the bond for R2.6 million. In 2019 the outstanding amount on the bond was +-R77,000.00, Standard Bank has now added about R100,000.00 on the bond for the outstanding insurance premium. My question to them is 1. how can it cost R2.6 million to rebuild a house that was valuated for R850,000.00 in March this year 2023. 2. Why should I have life cover insurance for R2.6 million on a bond of R210,000.00.