Making peace early
From the perspective of the victim of the breach of contract, there are various options you can take. The line you pursue depends on who the dispute is with, the subject of the dispute, the strength of your position, the general commercial circumstances and the result you want.
Generally test the waters
Depending on the strength of your claim for breach of contract you may wish to wait to see what the response is from your contractual counterparty after your first complaint. Bear in mind there is nothing at law that requires them to make a response to a letter of demand. It is merely a claim you have asserted. It can be gloriously ignored by your counterparty. If that is the case then you need to make a decision ...