I purchased the Non contact infrared thermometer ( the item I received is called Blunt Bird DN-997). I don’ see where it can be changed from Celsius to Fahrenheit. The instructions are difficult. Is their a phone number for this company. I can’t even get to chat with anyone from the company because no one responds. If I can’t get it figured out and if I can’t talk with someone, what will I need to do to return and get my money back?