一般来修东西都是当场付款或刷卡的。如果他说他修了,你们没给钱,他怎么就走了呢?他的invoice 有类似于"please remit your payment to such and such party at following address by such and such date"之类的话,即,指望你事后寄过去的意思吗?另一种可能是,他承认没修好,所以没拿钱就开路了。那他还写什么invoice?