Company saying they are the best. LOL!!

I think this is a company with the worst customer service ever. Bought a car three months ago for sister on my name but had to install the tracker on her name. At 4 or 5 occasions they have contacted to complete the contract after installation where I asked them to call my sister as I do not have her ID or the car reg. They have failed to do so every time. Now - 19/12/18 - I phone the accounts mamager and as a customer am given attitude and told it is not their job to call customers. When I threatened to call back to have the tracker removed and going to another tracking company, she quickly called my sister. My sister was told that the person working with her account is not at work and she must wait and the phone was put down. I then called back to speak with a manager at the Boksburg branch who was not available once again. I can deal with this type of customer service .