Inflating my insurance premium and then JUST NOT RESPONDING to emails.

After my claim for a geyser was attended to, Standard Insurance suddenly re-assessed the replacement value of my property. According to them, the replacement value shot up from R1.5m to R2.6m within 2 years, and my premium increased. No additions/improvements were done during this time. Building costs DID NOT RISE this much in 2 years. Waited a month to get a reply to my email requests for an assessment breakdown document. This document seems to have some incorrect measurements and a large value for improvements that do not exist. Send emails in this regard on 16 Aug, 28 Aug and 15 Sept. Till date (26 Sept) NO REPLY on any of these emails has been received!! I am most probably over insured and have to pay an unnecessary high premium.