Upgrade request

[aifactory]

my current version is Version 8.12
i have emailed a support request that i need to upgrade i was answered that they can not guarantee that site will break .
While i was promised on purchase of the store that support will be provided i email and wait for months with no reply.
i will really appreciate help. i do not mind upgrading myself if given directions .
my store is doing well and i am settled withe its usage i like a lot of features and maybe am one of the oldest users of this software i can also provide support to new users. or create a documentation for its usage i need a response please!
my site is www.aivault.com/store