Warranty and Guarantee seems to mean nothing

Purchase a Mellaware glass red kettle one December 2017 with 2 year warranty. Took the kettle back as per Mellaware guarantee instructions to the store as the lid popped off, store had a replacement but said the barcode changed so they cannot replace the kettle without me paying in R150. Guarantee says it will be replaced. Called Mellaware who advised store should have replaced the kettle but they will take it up. 2 days later still awaiting a call even though two follow up calls made and messages left. Shocking service .