How long after payment do you expect your product to be mailed? How long would you wait before registering a complaint or contacting your credit card?
If something takes longer than a month, the seller is obligated to inform you unless the time period is specified at the time of the purchase.
In some states it is required that the seller inform the buyer of any delay and there is usually a certain time period where the buyer has the option to cancel the sale. Now when ordering custom made whistles from makers that take more than a month for delivery it is customary to be given the estimated time period that the product will be delivered.
If the vendor in question has a website, you should look for terms of purchase - it’s a good idea to review this before making a purchase.
Remember that differnet whistle makers and vendors have response times that vary from a few days to two years. Most of the long term vendors (two months or longer) do not take money up front or sometimes a partial payment.