Sudden price increases in the process of buying

When I put in my details to pay it said all the prices had changed and everything had gone higher Items in this order 1 Fellowes HFC Free Air Duster - 350ml Fellowes HFC Free Air Duster - 350ml R 169.00 1 Casio FX-82ZA Plus II Scientific Calculator Casio FX-82ZA Plus II Scientific Calculator R 279.00 1 Casio FX-82ZA Plus II Scientific Calculator Casio FX-82ZA Plus II Scientific Calculator R 279.00 1 BIC Colour-in Backpack, with Aquacouleur Pencil Crayons and Visa Felt Pens BIC Colour-in Backpack, with Aquacouleur Pencil Crayons and Visa Felt Pens R 69.00 1 BIC Colouring Limited Edition Case With Three Colouring Packs and Activity Book BIC Colouring Limited Edition Case With Three Colouring Packs and Activity Book R 89.00 1 Croxley: Mini Highlighters Pack Of 10 Assorted Croxley: Mini Highlighters Pack Of 10 Assorted R 65.00 3 Parrot Whiteboard Markers (6 Markers - Slimline Tip - Carded) Parrot Whiteboard Markers (6 Markers - Slimline Tip - Carded) R 87.00 1 Meeco Carry Folder - A4 - Assorted Pack - Pack of 5 Meeco Carry Folder - A4 - Assorted Pack - Pack of 5 R 35.00 1 Paw Patrol Girls 3 Pack Toothbrushes Paw Patrol Girls 3 Pack Toothbrushes R 25.00 1 CellTime X-Stand-2 Adjustable Plastic Foldable Cool Portable Laptop Stand CellTime X-Stand-2 Adjustable Plastic Foldable Cool Portable Laptop Stand R 149.00 Sold by CellTime 1 Bath Mat Paw Patrol Girls Bath Mat Paw Patrol Girls R 105.00 1 Paw Patrol Skye and Everest 200ml Tumbler Paw Patrol Skye and Everest 200ml Tumbler R 29.00 1 Paw Patrol Lunch Bags - Junior - Girls Paw Patrol Lunch Bags - Junior - Girls