OM unilaterally changing policy maturity date

I took out an education policy in 2002, which was supposed to run for 18 years (January 2020 maturity date) as per the contract. However, when I contacted Old Mutual on 23 Dec 2019 to inquire about cashing in the policy, the call centre agent informed me that the maturity date has (unilaterally) been changed by Old Mutual to August 2022 according to her system. This is ********* as the contract clearly states 18 years starting from 2002. I need to cash in the policy urgently as I have a child who is going to varsity now in January. The call centre agent even had the audacity to suggest that I should withdraw a portion of the policy and let it continue until 2022. Please note that I do not wish to withdraw a portion of the policy and continue with contributions until 2022 as advised by your consultant. All that I'm asking for is for the policy to lapse in Jan 2020 in line with the contract, and for the funds to be paid into my account ASAP. I sent an email on 23 Dec with my policy number and ID number and no response to date. The call centre takes no less than 20 minutes to answer when I call.