My worst interaction

I did an operation at Lenmed lenasia in 2019 April and all went well. Today 2020-06-19 I receive emails and smses that I owe some out of medical scheme fees. The tone of the email demands immidiate payment. Why am I only being told this now after more than a year. I called to find out and spoke to a woman there(I won't call her a lady because of how she spoke to me) who says she doesn't know why they took so long Bt her system shows that they sent me an sms in November last year (wich I don't remember receiving) she couldn't have been anymore less interested in what I had to say and told me she recently started doing discovery and doesn't know why I wasn't told in due time. I have always gone to lenmed lenasia and I trust them with my kids, I recommend them to friends and family. Bt this marks my last time going to them. I made the payment and I'm done with that hospital. The woman dealing with discovery medical aid is a sour disrespectful person. She needs an attitude check.