Unreasonable charges on my account

I paid my water account on the 28th of March at an easy pay station and due to this it only shows on my account as being paid on the 1st of April. Due to this I was charged R8 interest. On my account was a R100 deposit increase and a R98.32 \admin fee". When I queried this I was told it was because I did not comply with sending proof of payment.<br> I feel like I'm being robbed being made to pay R200 extra on my next account because my payment shows one day after month end :( are they really allowed to make charges like this?"""