Horrible experience

I am having a bad experience with tracker,my tracking unit isn’t working properly,I reported this about 3-4 weeks back,all they keep on telling me is that they’ve restarted it it’ll work,the problem has been going on for some time now,yesterday I called in and spoke to a ‘Pamela Sibiya” who told me that they’re gonna have to replace the unit at R550 told her that I’m not gonna pay that as it wasn’t stipulated in the contract,she said she’ll go confirm on the “signed agreement “ and give me a call today,all of a sudden in morning I’m sent and email Kindly provide us with contact details and the address of where the vehicle is. There will be a service fee of R550.00 please approve. Thank you. Regards, Pamela Sibiya Customer Services Agent Tracker Connect Pty Ltd