NESTAR REFUSES TO REIMBURSE ME FOR THEIR ERRORS

NESTAR Refuses to stop billing me for their own Error.

The Company gives me a run around sending me from 1 department to the next with no existence.

I was using their tracker for 3yrs n I was changing vehicles I asked them to remove it to from old vehicle to new vehicle. The consultant said he will install a new tracker instead of moving it and it is an upgrade with lesser value. I agreed. Deduction came they deducted the previous amount even though we agreed on a different 1.when I called they ignored me. Following month they deducted double amount when I called again they gave me a run around after days of trying their consultant told they charging me for 2 vehicles ?. They said they going to charge me again. Their Manager keeps ignoring me. Help me