Oyi Medical Card ****mers

Worst experience ever, hoping that you will assist me to get my money back I have an account with Oyi, for some time it was working with no problems, until early this year when it started declining with "insufficient funds"when I made payments and there was money in the account. At first they used to say it's a technical error not from their side and unable solve it but they keep on debiting from my account. As time goes on, I would see that it's multiple people complaining. I have called them many times for a refund with no success, they promise that they will refund me and it's been about 4 months now. At first they used to say the delays of refund are because of backlog they have, but now I see it's there is something fishy going on. Can you please assist me in this regard