Endowment Policy Worthless after 28 Years

I took out an endowment policy from Sanlam over period 1 April 1991 to 1 April 2019....Policy name -"THE ONE POLICY FOR ENDOWMENT"- with (a) Life cover (b) Disability Cover and with waiver of premium benefit. I have been faithfully paying my premiums of R 57-59 per month expecting my money to at least help me in my old age - I have never borrowed money from this policy and I have never missed a single payment,- the premium might not sound like much today, but it hurt badly at every month end in the Nineties and even in the early 2000's it was a big amount every month. I paid that premium for 28 years, a total of R 19350-00 During mid April 2019 I was looking at my policy and found that the policy had matured on 1 April 2019 and I had not been contacted by Sanlam, so I queried it, and on 20 May 3019 I received a reply that this endowment policy that I have so faithfully been paying for, - was in fact not paying out anything on the maturity date as it was worthless Sanlam says they realise that I was expecting a pay out on the maturity date so they would offer me a EX GRATIA amount of R1691-46. I am totally shocked by this ,- How is this possible? Why was I not warned about this type of ****, I was told at the time that If i took this Endowment it would provide a good payout when I would really need it pay off debt and to make my retirement easier, it would also cover me in case of death or disability, if I did not query this I would still have been paying this premium every month.................please help me