My mum went to Lenmed Hospital for a scope

My mum went to Lenmed Hospital for a scope. After a year I got an email from debt collectors to make payment for outstanding fees. Lenmed never sent any invoice.This lady that works for debt collectors Laiken Dawson emailed me to make payment. In my emails I told her that banking app I cannot pickup RMB bank. She never rep****.I was going to do payment over 3 months but decided to do the full payment. I went to my local bank.They were also confused about RMB bank and eventually told me it's FNB.I am appalled at the bad feedback and communication I received.