Gadget Boss - Confusion

They do not honor the advertised price. An NFC Bluetooth receiver was advertised on Facebook marketplace for R89. Confirmed pricing with Kofi via Facebook messenger. Contacted the store directly and confirmed that stock was available and the price was correct. After making arrangements to collect and then driving to their warehouse, I was told that the price advertised was incorrect - this despite me confirming twice, once via messenger and once telephonically that the price was R89. After refusing to accept the blunder a small compromise was made, still to my disadvantage. In addition, I have yet to receive the invoice which was supposed to be sent to me via email, for warranty purposes. Trade with caution.