Charged wrong bid price

I got invoiced a higher bid price for a vehicle bought on auction in Secunda on 21/10/2015. The bid was 30000 but was invoiced a bid price of 35000 + charges. When inquiring was told first that they will listen to tapes. The auctioneer when into the caravan for 2 minutes said she listen to the tape and that i bid 35000 to which i responded \can I listen to the tape\" to which he responded they are busy and later in the day I can listen to the tape. Later I was told by the auctioneer that the bank has a reserve on the car of 36000 and the best they can do is 34500 to which I responded I bid 30000 because I only have 30000+charges. The auctioneer then tells me that they have to cancel the deal so I said fine and that they will be pay my deposit back. Three days later they refuse to pay my deposit of R10000 because they tell me that I cancelled the deal. Long story short I lost the 10k. Tried using a lawyer to recover the 10k and lost even more. Jet Park Auctioneers is not even registered with SAIA. "