Benefits depleted eventhough I didn't use it

It's been 2 weeks and multiple calls to the call centre and yet my issue is not resolved. No one is getting back to me even though they advise that I will get feedback. I am on the Essential Smart plan. I am well aware that my plan doesn't cover fillings for dental. I went to the dentist in January for a filling. I know I am supposed to cover the bill. However when I check my benefits, it shows that my dental benefit has been depleted even though I haven't made use of this benefit this year. It clearly shows no payment was made to the dentist in January, so why is my benefit depleted? I have made numerous calls and logged queries but no one is getting back to me. I'm just wasting my airtime calling everytime and having to explain this story to different people. Such a waste of time really. Can I please get answers as I do not see why my benefit is depleted even though I did not use it