Other Fuel System Pump problems of the 2006 Hyundai Santa Fe

After engine is warm, about 20 minutes later, there is a gurgling in the fuel tank when the key is turned on (before and after the engine is started). I think it is fuel being returned from the engine. I have had it in two different Hyundai service shops, with the fuel pump replaced twice, and a fuel pressure regulator replaced. Having given up, both shops contacted the district Hyundai office and a field service adviser told the local shops to show the event as "normal". It is not normal and I think the Hyundai district office is hiding the problem. Could be a fuel system problem and could be a safety hazard if fuel starts leaking. Both local service departments now show the problem as "normal" and nothing more will be done on this problem. I believe a recall for this problem is appropriate.