Repair for High Pressure Gas Stove

[ilostmypassword]

For years we've had a Smeg stove and the gas never worked properly. By accident, the company charged with repair and maintenance of said stove, once sent us a competent repairman who told us that the stove had been misinstalled. Apparently fitted with low pressure gear. He told us what was needed and promised to return with the necessary gear. Naturally, the company refuses to send him so we are stuck with the same incompetents as before. Does anyone know a knowledgeable repair service that can handle this. We spoke to Home Pro and they ended up recommending the company that we already have been using.  

[lopburi3]

I seriously doubt any home stove needs the high pressure supply used by the huge Thai wok food stalls so be very careful.  But there may be different nozzles for natural, propane and LPG type gas supply?  I have a 35 year old Kenmore BBQ that had to drill nozzle larger to get it operating properly here.