BP Groblersdal charges an extra 16c a litre of 93 unleaded petrol - so R16.00 per litre instead of R15.84

We filled up our car with 93 Octane unleaded petrol at BP Groblersdal on Thursday 2nd Jan 2020 and were shocked to find out that we were charged R 16.00 a litre of 93 Octane unleaded petrol when the announced petrol price for inland is R 15.84 from Wed 1st Jan 2020. I have checked with many other petrol stations, including other BP petrol stations, and the price everywhere is R15.84 per litre. Is the BP in Groblersdal *********** its customers by making a quick extra few cents per litre???? I thought that there are only 2 official petrol prices for the various different Octanes of fuel, a coastal price (Cheaper than inland) and an inland price. As announced by the energy department, the inland petrol price to 93 octane unleaded petrol is R 15.84 (down 4c a litre) from R15.88 in December 2019. Needless to say, I contacted the manager of BP Groblersdal, just to be told that they are in a different zone and therefore they are allowed to charge more - it is a levy added for them - REALLY???? I have contacted BP South Africa with proof of the price we were charged at their franchises petrol station in Grobersdal and await feedback.