I just paid in full my balance on buying my military time back, I am a GS now. In short, I had 13 years active duty, cost me almost 12k, lump summed it with the online payment option.

Has anyone been through the process fully, and how did you get confirmation? Its the government so I'm expecting this to take forever and to speak to 100 people til I get what I need.

I have an email receipt, should I write them a letter to get confirmation of this? Or can I fax them something, asking them to reflect that my time has been paid in full? I'm staying proactive with this, I dont want a horror story of retiring and them saying I never paid it back.