Bad customer service

I installed my gate motor 3years ago,Las year in August I had a problem with it,they made me pay R1100 to repair a PC Board. immediately after a day or two the initial problem emerged,they claim that the roots of tree close to the gate is the cause,it will be fine if roots were taken out and the rail be fixed,then they will come to reset the motor,the roots were taken out by the municipality,the rail was repaired,I called them first,twice and many times they gave empty promises of coming to check the motor,till now they drop my calls and I am stuck with a motor that doesnt work even if I paid R1100 to repair the PC Board which am not sure if it was repaired or not,according to people who use gemini motors,5 years is minimum guarantee for this motors. What must I do to get my refund of R1100 I paid for nothing?