Poor services provided

I registered to BID online for auctions that was held on the 22nd November 2022, and paid the deposit amount of R7000. I placed the bid on Fordfiest 1.0 ecoboost 2013 model with the amount of R 88 000 and the bid went up , I then decided to stop bidding at the R88K due to my budget however the system continue to bid on my account and closed my Bid at R100 000 unware. On the 23rd November I was surprised to get an invoice from Tirhani auctioneer for the amount R 117500.00 . I reply to the email and advised them what happened but they told me that if I don't pay the full amount I'll forfeit my deposit. I'm aware of the contract signed regarding the dep but in this case it was the system that occurred in my account by continuing placing bid while I'm not aware. I asked for refund however they just told me that I'll forfeit my deposit and they'll block my account . How on earth can run a business and treat your customers in this way …I wont recommend this auctioneer to anything. They manipulate system in the name of signed agreement just to ensure that we loose our hard earned cash. As the name says TIRHANI they are working indeed...