BAD SERVICE AT SPEC SAVERS THE GLEN

I got my pair of glasses from Spec Savers The Glen in 2022. I was told that any shortfall that the medical aid didn't pay for would be covered by loyalty points. I was surprised when I received a message from debt collectors, Collier and Malan, in December 2024 claiming that I am owing Spec Savers an amount of R1554. I told the lady that I didn't know anything about that debt. Spec Savers The Gen never sent me a statement of account. I told them to ask their client to communicate directly with me, but they didn't. The debt collector offered to send me the statement, and they have been threatening to list me with the credit bureau. Is this how to do Business? How can I be harassed for a debt that no one told me about? Why did they lie to me and say the loyalty points will cover the shortfall, or that was just a marketing gimmick?