Poor installation and service practice

I purchased a brand new DEFY Inverter air-conditioner unit from Makro and paid for Servisure to carry out the installation. After the initial installation, the unit began to operate poorly and the Servisure team came out and found that there was a leak and that it had been installed poorly. After rectification, the same problem has now returned. After arranging time off from work, Servisure just can't seem to comply with their appointment schedule to come and rectify the matter and continue to provide excuses, empty promises and poor service delivery. This poor service has been a complete nuisance and has now incurred financial losses. I have lost faith in Servisure's credibility.