Virtuemart site - tax calculating wrong

Hello we need a pro who can asap fix the error on virtuemart. The tax + 25% is not calculating so please fix this issue. we make a many changes in showing price (css) but this is not working. The clue is - tax is set up to + 25% but he is calculating it like -25% and then for example the cost price is 100 and he is showing the base price 75,00 and final price is wrong.....cost price is 100, base price is 100 and final price is 125. Total price $5 + bonus + best possible review.