Being billed for an inactive line for 1 year with nothing but excuses

I have an active military family member on my mobile plan, when they were ordered out of the country I was told we could suspend the service on the line as long as his device payment was still made monthly. They asked for copies of his orders, which were provided multiple times to multiple agents at multiple stores. Every time I was told that the billing would stop and I would be refunded the paid fees any day now…just keep checking your account. One agent even stopped replying to my emails without doing anything. It has been a full year now of paying for an inactive line. I could have just paid off the device and cancelled the line but we were told some bs how they support military and this is a complimentary service…from a customer of over 20 years because there was never any other options available, but not anymore. I want my overbilling refunded immediately and service cancelled