Engine Burning Oil problems of the 2014 Ford Focus

We bought a 2014 Focus on March 27, 2015 and drove the Focus without problems until January 2016. On February 22, 2016, the engine oil warning was flashing. Almost all the oil was depleted. It had been less than 5,000 miles since the last oil change, so it was strange. We took our car into kayser Ford the next day. They couldn't find anything suspicious. It was concluded that not enough oil was filled previously. They then filled oil to the max level. On March 10, we checked the oil level after 500 miles since the last change. The oil level was low. We went back to kayser, and they found that the oil level varied. They suspected an oil burning problem. We then made an appointment with an engine specialist and had 2 quarts of oil put in. On March 15, we visited kayser again and had the engine specialist check it. They again felt that not enough oil was filled the last time, and we should bring it back after another 500 miles. The last full oil change was done by kayser on February 23. We made another appointment on March 24, and we then went on a 400 mile trip. After we arrived and checked the oil on March 20, the oil was much lower than the minimum level. Since it was Sunday and we did not want to risk an accident, we added Ford motorcraft 5w20 oil. On March 24, we went back to kayser and the technician said that we had to come back again later because we added oil since the last service. We showed evidence through photos, but he refused to do a detailed diagnosis. He said that they had to report the exact amount of oil consumption lost in order to do more. We had to visit family living about 170 miles away, but we did not feel safe driving that far. We asked kayser Ford to provide us a rental car, but they wouldn't. We made it to our destination, but we had a low amount of oil the next day. We then took it to a nearby Ford dealership for a fill up.