The Discovery ******* strikes again

After changing from one of Discovery healths highest plans due to my funds always being depleted for some stupid reason to a lower plan (after a lengthy process of affidavids, letters, confirmations, salary letters, bank statements, gradings etc), I was now sent a sms saying I owe Discovery almost R4000. Even though no one ever told us this during the 10+ calls to change plans nor was it indicated on any letters. Do proper research before joining Discovery, they will hurt you financially.