Incorrectly spelt name

I've been reporting their wrong spelling of my mother's Nguni name on the policy documents for three times already. I spelt the name over a call - telephonically, texted it on WhatsApp and wrote it on an email for them to see how they should write it but they keep sending policy documents with an incorrectly spelt name. This is the same thing that they will use against us when they have to payout within 48 hours, let alone the disrespect this is!