Old Mutual doesn't want to release my mother's investment funds after it matured.

I write this with a very heavy heart. My mother had an investment with old mutual which matured on 1 February 2020,on the day it matured we went to OM vereeniging branch to fill out whatevet necessary forms to release her funds. We were taken from pillar to post, had to obtain cession releases from Nedbank which took up to a month, that was finally done in the beginning of March and OM was informed. We now received a letter from OM saying that my mother's funds have been transferred into a money market fund without her knowledge and acknowledgement. My mother r wants her money, she doesn't want stories about funds. I get the feeling OM does not want to release her money hence all these delaying tactics. Can someone please assist as this has gone in for too long and causing my mother distress!!