Unfair treatment - Misinformed of the eye test cost

Good day,

I went to specsavers Southgate on 30 May, Saturday. I am using Discovery medical aid and the lady at the front told me that they are unable to check for me if my medical aid covers costs on a weekend and still recommended that I do the eye test and they will check everything on during the week next week and it should not be a problem. I proceeded and had done the eye test, Then on 3rd June I received a call from the finance department from Specsavers telling me that my medical aid does not cover me and I had to pay R500 cash. I was confused because I was never told about this and I made it clear to the receptionist there at South gate I am using Discovery Smart Essential, This is absolutely unfair and if my discovery option did not cover this, they should have told me. Not enough information was provided to me that if my medical aid does not cover, I will pay R500.00. Which I do not have. Please HELP! I frustrated and this is putting a financial burden on me. Thanks, Tumelo Nkotsi