How do I get myElectric Weed Sweeper Repaired?

Model GARDEN LINE G1509/78506/N1CT-YL-140 it WAS PURCHASED FROM Aldi in 2017 and is still under warranty but as i no longer have the receipt they will no longer repair it.The machine switches on but as soon as i try to use it ie put the wheel on to the weed it stops. It worked well when first purchased but would not start last year.I hope you can help.