Bonitas not paying refund liable

Bontias medical aid is making it impossible to receive a refund that they are liable for. I am the Executor on my late moms estate. For months on end I have been sending through the required documentation for the balance due on the membership to the Estate late account but I am making zero progress. It took over a month for them to come back saying the now want colour copies. Then it's saying the certification has expired. Then it's 2 family members for verification. Then we're back to the beginning saying they don't have the documentation. On each occasion they require multiple working days in which to respond. I have been phoning their customer services daily, but the standard response is that they don't have a direct line to the Finance department and that they will escalate, but nothing ever comes of it. It feels to me like deliberate delay tactics so that one gives up. Looking at all the complaints on this forum they will apologise and ask for the membership number. Here it is: ***9