I would have called. There's too much in the pot to fold.
I have the pot figured differently from you. You said three of you contributed T300*4 each on the first betting round, T300 eacn on the second betting round, and T600 each on the third betting round. Then on the fourth betting round, you checked, one villain bet and the other called, that makes T400 in the pot on the fourth betting round before if was your turn to close out the action. Presuming the blinds both folded to the action on the first betting round, they left a total of T450 in the pot.
T450+T300*4*3+T300*1*3+T600*1*3+T600*1*2=T7950 in the pot at the point you had the option of folding or calling T600 for the final bet.
7950/600=13.25. You were getting 13.25 to 1 to call the final bet (plus your own money back for the final bet). That's assuming the blinds both folded.
But even if somehow there was only T6500 in the pot, you were getting over 10 to 1 to call (plus your own money back for the final bet).
What's confusing about it is the caller. You probably figured the caller had to have something decent to call, since you were still in the action.
That's actually a reasonable assumption unless the caller is either very good or stupid. Either of those two extremes might call from mid position with you yet to act. The very good player might do it because he thinks the player betting is bluffing and if he merely calls, you'll assume he has something and you'll fold. The call here from a very good player is like a bluff on top of a bluff. The stupid player might have some other motive for calling.
The call bluff on top of a bluff is actually not an uncommon move. With two pairs, aces over, you just have to call too. You're stuck in the pot.
If it makes you feel any better, I've done the same thing (but not for a while).
You'll remember this experience and you'll be a better player for it.
Buzz