Not Helpful Customer service

I always pay my Truworths and Identity accounts a month in advance eg, on 12 April I paid for May which it reflected on both apps that payment due for may was R0. On 8 may I went to the stores and paid both accounts but it's still shows June payment is due on the app???? I called customer care and the lady I spoke to was not helpful at all!!! Kept telling me the payments I made on 8 May was for May because June is still outstanding. I was very long on the phone with the lady my airtime got finished in the middle of our conversation and she didn't even have the decency to call me back.