There is so much to know before you decide on who to work with as a supplier. a drop shipper and or supplier holds the future of your business in their hands dictated by there actions and what they ship.
The down side of drop shipping is that you the actual reseller never see, touch feel or hold the item. so it is a clear case of your buyers word against a supplier.
Some buyers are looking for free product or can simply be a case of, "you cant make everyone happy" but, you cant defend the supplier, the product or your self if they make a complaint against you or the transaction.
Now being you are a new seller, your order volume would be naturally lower. and each complaint make a big wave against you. enough complaints and you are done.