Very eager to cancel my medical but do not want to refund me

Somehow 1 payment did not went off my account for Medihelp, we got a call from them 1 month later and was told 1 payment was missed and we need to make a payment, we did make a 2 payment within a couple of days, after payment were made they told us that they have cancelled our medical from the month of April, ive sent the proof of payments, after they recied it they told us that we need to make another payment in advance to reactive our medical, i did respond by asking them to refund me the money paid as i do not owe then any monies, they owe me a refund on one month as the have desided to cancel the medical without notifying me. We do not get any feed back from them, i need to sent mails every time, they were very quick on mails when the wanted money.