2 years are you sure as a ban is forever.
Doing something once / 1 time does not lead to a restriction or ban unless you are using code injecting software or cheating in some way.
Connection based restrictions or bans you are given a warning about your connection first before any restriction or ban is places.
Bungie investigates accounts before they hand out any restrictions or bans. After investigating your account, they found a reason. They will not remove this restriction/ban. On the occasions they do respond, the answer will give a date and a very brief reason which will be one of the following below.
1. Cheating
2. Any software being detected by Destiny while it's running. These could include Trainers, Aimbots, Auto-fire, Mods, Graphics Hacks, anything that injects code into games.
3. An unstable connection is having an impact on other players.
[url=https://www.bungie.net/7_Destiny-Account-Restrictions-and-Banning-Policies/en/Help/Article/11929]RESTRICTIONS AND BANNING POLICIES[/url]
You agreed to the license agreement.
[url=https://www.bungie.net/7/en/Legal/SLA]Agreement[/url]
[url=https://www.bungie.net/en/Help/Article/46101]DESTINY 2 PC AND THIRD-PARTY APPLICATION FEATURE COMPATIBILITY[/url]
Your account is done for good.
https://www.bungie.net/en/Help/Article/11929
There is no chance of un-banning your account. Also they do not just ban you for 2 years. If you received a ban, that account is banned for life.
Unless of course, this is a Steam VAC ban ... in that case it was NOT Bungie that banned you but Steam itself.