Hyflo supply wrong hose & want client to pay 15%

Specifically requested HIGH pressure fuel line. I explained use is for a pressurised fuel system on a high performance vehicle. I received standard SAE 30R7 line that is not suitable. I want to return the incorrectly supp**** hose and Im informed I will be charged 15% . What BS. Will rather deal and recommend another hydraulic and pneumatic hose supplier