Beware of Netstar

In August I contacted Netstar to have a tracker installed in my car. I received a verbal quote for an amount in the region of R5600. The reason why it was such an amount was because I paid the full 3-year subscription upfront and they gave me 3 months discount. I confirmed twice what the amount was to be deducted from my account. On the 2/10/2020 they deducted an amount of R7200 which is R1600 more than they quoted. From time of installation until debit order was deducted, I received no written quote or invoice from Netstar. Upon enquiry why this amount differs from the one that I was quoted telephonically, I received an invoice. This invoice reflects installation and other costs which were bot disclosed before. I feel that I have been ******* into a 3 year contract.