Exorbitant increase in premium for 2021

I find it utterly disgraceful that momentum short term insurance decided to increase my premiums for 2021 by 8% even though I had no claim for the previous 12 months and no logical alternative explanation from their side. Supposedly this increase was app**** a cross the board on all policies! After phoning momentum about this they were only ably to reduce the increase to around 7%, still twice the prevailing inflation rate for this year. Considering the economy and the reduction in claims due to the lockdown I cannot understand how Momentum can justify this increase.