Always react favorably to customers who are calling and are worried because their other vendor missed a target or deadline. Help them out. Given the fact you can react and satisfy the new or current customer, do so, get the purchasing agent out of a bind and you may pick up a new client or additional work from your efforts. If you cannot perform the work or do the job for the customer, give him several referrals to help him out. Afterwards, call him to see if he found a source and if he did not, provide him with more options if they are known. Help him now so he remembers you later.