Even if your account and pet had reason to be returned, it's too late now. 90% probability it's been purged.
TNT typically states they cannot retrieve accounts frozen for older a year, but many are skeptical that TNT are just full of shit, since sometimes they say the same thing after 7 months, while other times you have your account returned to you in 1.5 years. But 3 years is almost complete certainty it's gone.