Avoid Bid or Buy, they post additional charges underhandedly in the middle of the delivery process

I purchased an item online and was requested to pay an additional delivery fee to my door. I paid the full amount. All prices were quoted and paid for in Rand, so it is assumed that prices are frim in South Africa. 10 days latre the firm wanted another fee for customs clearance, this is unacceptable. If they quote a delivery fee, this fee MUST include all charges. At no point did Bid or Buy indicate that they are importing the product and I am liable for clearance fees.