Netwerk Koeriers Fraudulant Invoice

I have recently had an engine shipped through Netwerk Koeriers. Engine was loaded and delivered to my address as agreed, I then was issued with an invoice which I paid in full. I noticed something fishy with the invoice as the calculated VAT and admin fee percentage was the same value, and that led me to scrutinize the invoice. As calculated both values were an abnormal 17,6% instead of the stipulated 15% even indicated. As I noticed this I then raised it with Netwerk Koeriers and spoke to Annemarie Mans. She then confirmed that normal VAT is charged at 15%, yet on the invoice it shows different. Also spoke to Juliet who never returns any calls. After numerous calls back and fort I spoke to a Karla from their accounts department, she requested I send her the so called 'faulty invoice' for them to investigate. She then replied with a forged invoice, where they literally used typex to alter the numbers altered and now this, according to her, is correct one and the invoice I possess is wrong. It appeared that their head office took it up with their local branch in Kathu, managed by a very rude Mr Jas Mans, husband to the person that intentionally increased the values as per invoice. He was shouting out of guilt and used some crude language asking why I did not negotiate with them before I reported to their head-office, which I have done and they did not care to rectify it. Mr Mans suggested that I provide him with my banking details for him to refund the overcharged amount. I pleaded with him that it is not about the money, but it is due to the fact that it is in total dishonesty and a fraudulent act what they were doing. And I'm sure I wont be the only consumer that were fraudulently invoiced from the Kathu franchise or even all Netwerk Koeriers clients, they wouldn't notice unless their invoice is scrutinized. Upon interacting with Netwerk Koeriers they sure lack customer service, which should be their first priority, as well as honesty. Had they been honest in the first place this review would have never made it this far. They also just form part of the many business out there exploiting this Lockdown Price hikes. To the rest of the consumers, please beware of companies such as Netwerk Koeriers. I have however reported this to the Consumer Goods and Services Ombud and hoping for a speedy resolution.