Q: Gas gauge not registering fuel level

I recently noticed that the fuel gauge had not dropped to the expected level after driving 300 miles. I stopped to refuel and that was so fortunate because the tank was almost empty. I called the dealership and they called back a week later. They had me bring in the car (had to drive to another city). They did give me a loaner car while examining mine and four days later reported to me that it was an issue with my make/model cars. Evidently there is something in the tank causing the problem and the whole tank needs to be replaced, they said. However, they continued to explain that there were no available replacements tanks. They said it would be more than a month’s wait until one became available before they could install a new one. While I am waiting “impatiently!” could you please tell me if you know of a different solution, instead of my having to wait on a new tank?