Pathetic Service basil green ford

Poor pathetic service feedback , my 2019 ford 2.0 XLT double cab with 35000km yes 35000km went in 4 times in a matter off 2 months for a week to 2 at a time with a fluctuating fuel gauge fault and my vehicle was handed back to me by the service manager acknowledging the fault and insists I must report to Ford SA and after logging that fault he still hasn’t dealt with my vehicle problem nor has ford sa come back to me . It’s another 4 weeks and 3 messages later still no feedback. Should I drive my vehicle through their showroom for them to sort out as I cannot drive my vehicle becos of the fuel gauge from 600 km to 15/10 empty and back to 500 not knowing exactly how much fuel is in and he and a tech says it’s normal .