Digital Printing Industry

I have a factory in Asia for which we have big printers and many digital machines, For that we need printing parts, inks etc. We have been ordering from one company (i will not say full name) but its digiprinting thing. They always charge and never supply product on time, and argue that they have things out of stock, however while ordering their systems clearly says that product is in stock. That effects our work and also our time in arguing and they charge double shipment and therefor fighting for shipment charges as well. My question is if any of you know from where we can buy products like printing inks, maintenance kits, parts like filter lapms etc. Please help me. Best regards FA