Bad Client Service and business practices

I requested a quote for a replacement HP Laptop keyboard and received the quote as requested, I continued to pay for Item as per quotation. When we wanted to collect the part we were informed that the price for the item has changed and that we must pay the difference or they will not release the part to us, I informed them that they quoted us and we paid for parts quoted at the rate quoted but, they would not budge, I quoted my client on the replacement parts and had no choice but to pay the difference so I could supply the part as it was urgent and subsequently ended up supplying the part to my client for less than I paid for it, I unfortunately cannot tell my clients that price has suddenly changed and that I will not release parts until they pay the difference, Once you quoted and client paid you are responsible as supplier to honor your quotes.