The highest trading fee they charge according to their website is 1% and the fees for using instant buy/sell directs us to this page. There is no mention of additional fees.
https://www.luno.com/en/countries#trade-fees
Looks like something dodge is going on. Instant buy/sell on the exchange works correctly for me though, as per the fee schedule. I thought the fees charged would be exactly like placing an instant buy/sell order on the exchange. Hence I told my friend to just use the instant option to sell quickly with a 1% fee, not knowing that they would be charged 2% (in which case I would not have told them to sell as 2% is ridiculous).
Never use instant Buy......or Sell form wallet
During one drop I saw it at 213k and I said instant sell at 210. Took literally one second to enter my pin and press go. Sale went through at 186 799. Price never went below 200......so go figure how 0.013 bitcoin could not be matched to any buy orders above 186.
Tried to buy back in at 213 again and instant buy in at 219.
Lesson learnt the hard way