Builders Warehouse' GetitDone App and *********** call centre

I made use of the GetitDone Builders Warehouse app. An "accredited" service provider was dispatch by Builders Warehouse to install a pool light which was bought at a Builders Warehouse store. Now, a few months later the pool light is floating in the pool rather attached to the pool wall. To get Builders to sort this out with the service provider is now going on for 3 weeks. I paid R600 to do this simple job and now the call centre can't even resolve my complaint.