We tried to add a 4th line today to give my stepdaughter a phone for her birthday. We have been Sprint customers for almost 10 years. We were told that we had to wait a month to add another line because it hadn't been 9 months since we added our third line. Mind you, Sprint overcharged us for about six months in a row to the tune of $800 and it took me over 15 hours of calls to customer service to finally figure out why our phone bills were so astronomical. I do not understand the policy on adding lines. We were told that if we were brand new customers and wanted four lines, we would be able to get them on the spot. It seems that Sprint doesn’t favor their existing customers. Anyone have some insight on this problem or suggestions about how to get around this issue?