solenoid valve for oven taking two weeks to fix

Our solenoid valve in the lincoln II oven is broken and it has been 14 days and they havent fixed it I am in queensland Australia ,there is only one company in aus that has the contract for lincoln ,have called them 17 times but still waiting on the part they dont even know were the part is I assume it is coming from USA,any ideas or help would be much appreciated we are pissing a lot of customers off by only haveing one oven thanx Shaun