I used to be able to use 4G and/or LTE with a STRONG signal at my work place in New Jersey for the last couple years. Within the last year, my signal strength has decreased significantly and sometimes only 3G. My service used to be faster than the wifi available so I would disconnect from wifi if I wanted to get something done. Now, I have the hardest time sending even a text message let alone an iMessage. How do I report an issue with their coverage?