How did the hanseatic league punish those who did not follow their strict trade rules?

The Hanseatic League punished those who didn't want to follow their strict trade rules by stripping them their right to trade altogether.

t was in these equitable Courts of the Staple sanctioned by the Crown that merchants brought suit against debtors. The debtor might, in an appearance before the Mayor, acknowledge his debt and agree to pay. If he was unable to pay, his property, up to the amount of the debt, could be seized and sold by court order. These court orders were the infamous writs of assistance. When debtors were unable to pay and had no property, the Mayor would have the individual, provided he were a commoner, thrown into the town prison. If relatives or friends did not obtain release by paying the debt or furnish the prisoner with food, often not adequately supplied by prison authorities, the debtor likely died there.