UNINFORMED !!!!!!!!

I had my eyes tested at Specsavers Oudtshoorn, in 2017, via my medical aid, and i was made aware that there might be charges if i choose a frame that was not fully covered by my medical aid, however i was never shown the frames that was not covered by my medical aid. I a few weeks later i received a call from specsavers saying my glasses was ready for collection and there is R490.00 that i have to pay. I refused to pay to pay as i was never shown the frames covered by my medical aid, however i was informed. I never paid the R490 and left the glasses and i advised the them. I received a letter from a lawyer forcing me now to make the payment for something i dont even have in my possession, i feel it is really unfair towards me as i was never properly informed, and how can i pay for something i dont even have. Not fair specsavers!!!!!