Unhappy customer/client

On the 20th of December 2021my father received an SMS stating he is owing R5599.00 to my surprise i made a call enquiring about that amount they told me it was because he was not paying he's contribution hence he's been paying since each and every month they said from April he hasn't made the payments for 4 months I asked them to send me an email my father was working at the Department of Education and he retired on the ,31st of March so he started paying cash for he's Medical aid.on the email they sent me there was no missing payment but they kept on persisting by saying he is owing he must pay or else he's benefit will be suspended so even when we call we talk to different people Nd they singing the same song until one Consultant whose name is Bafana who told us they made a refund on he's account of R5599 which he didn't get that refund went to an old closed account from Standard bank Bafana advised us to go to Standard bank which we did but failed to get assistance because the account belonged to someone else than called Gems and Gems said we should pay that money which I find it very odd cos first of all we never asked Gems for a refund on anything now they made a mistake they want us to pay which is very unfair this Medical aid is nonsense I'm even thinking of changing it cos they not helping even their consultant are not professional they rude Nd full of nonsense only Bafana who saw kind enough to help us where the problem was please help us call peter