Pathetic after sales service from Kickstart Bike management and its owner

My partners and I have bought 18 bikes from Kickstart Bikes Midrand branch (SENKE SK 150-6) in October and November. One of these bikes had gone to Kickstart for electronic repairs twice already (Sandton branch) and the problem has not been resolved. It is currently at Midrand branch since 10 December 2018. It seems I have to request an update everytime without them updating me on the progress of the repairs (if any). Sometimes, my whatsapp message are read but ignored. The Midrand branch manager rarely keeps any promises he makes and I have lost any faith in this matter being resolved amicably. This has resulted in me losing about 2 months worth of income. I have a copy of the issues that I requested to be attended on the bike as well as whatsapp message trail.