********** sending me invalid invoices with overstated VAT

I have a package currently held up at customers. Sipho Malindi has sent me the invoice from customers. When I checked the invoice, the VAT was grossly overestimated. The total amount excluding VAT is R 469.20 but the VAT (which is an additional 15%) is reflected on the invoice as R 189.15. ***!!!!

The VAT amount is supposed to be R 70.35. Why THE **** are you charging me R 189.15 for????

I queried this with Sipho numerous times but he instead ignores my emails and keeps replying to his original email asking for payment.

Fed-Ex, get your **** together! How dare you try to de***** me! This invoice is invalid and SARS will not allow it when I have to claim the VAT. I need my goods ASAP. Fix this!