No response on an account query

Good day. I have sent TWO emails, one on the 26th Sept and another on the 2nd Oct. enquiring about a calculation amount that doesn't make sense. I am doing this on my mothers behalf as she is in a frail care center. The first thing that I asked was why she is paying quite a bit more than the R178.26 and now had to pay R304. Now the amounts that is DUE by my mom is R54.19 and R145.96. THIS DOESN'T GIVE ME R304!! Nobody is coming back to me on this. How difficult is it to just respond or tell me WHY??? I need an answer please.