I applied for a USDA loan through a new home builder but they aren't updating me regarding my loan

You say you applied through a builder ? is this accurate or did you apply through the builders preferred lender ( likely owned by the builder ) ....contact / call / email all parties that you have contact points for at the lender / broker ......call the sales center for the builder ...call / visit the builder ....do you have a signed contract for the property ? if so - they cant sell it to another party ...if you dont have a purchase contract or havent placed a deposit on the lot/ property - they likely can sell it .....is the location in a USDA approved location ?

Rarely is the builder, or the builders lender the best choice for home financing... Your statement about once sold, horrible service is typical. As with any customer service issue, escalating to a supervisor, if you can figure out who that is, generally is effective. You can also always change lenders... Good luck. I provide USDA loans in Minnesota, Wisconsin, Iowa, North Dakota, and South Dakota. Find my USDA loan information at https://firsttimehomebuyer-mn.com/usda-loans/ - Cambria Mortgage, NMLS 274132