A violation of the treaty by an individual vampire was punishable by final death. The ranking Bishop of Archbishop of the area where the offense was committed would call for a blood hunt then. Not surprisingly for the Sabbat, the Treaty was violated not very long after the Treaty had been signed ...
The Purchase Pact of 1803:
"Let it be known that forthwith, the Sabbat exists as a free entity, though the price of that freedom comes in the form of the sacrifice of certain rights.
On this, the 19th of September, 1803, all Sabbat in good faith and conscience do hereby suspend all grievances with other Sabbat.
Any Sabbat found in open violation of this agreement – e.g: any Sabbat making open war on another for the purposes of his own betterment at the expenses of the sect – is hereby declared forsaken, and maybe hunted for the blood in his veins. A duly recognized Bishop, Archbishop or other elder member of the sect, must pronounce such abandonment.
In this we are united. In this we are Sabbat."