Can't lay-bye one item because your stock room has no order

Well today I went into the store at PEP. I saw this cute boot I wanted to purchase. Financially you have to buy things according to your budget or what your able to manage. I am the only one working at the moment. I took these boots wanting to make a lay-bye as I am not able to purchase it. One cashier in the background said sorry lady you have to have 3 items at least. I then proceeded to ask another employee if you are able to lay-bye one item she said yes you are able to. I asked has your policy changed is this on your website?, to please help me understand why i am not able to lay-bye this boots? I then requested to speak to a manger. Her name is Chrystal she had on a pair of spectacles. I asked her maam please explain to me why I am not able to lay-bye these boots? Is this on your website, is this a policy?,what has change? She proceeded to tell me that it is due to packaging as they are unable to find smaller packages in their store room and customers dont want to wait that long. I said that this is unexceptable and an its unreasonable to expect a customer to now take items they never came for in the first place. It is not the customers priority or responsibility to ensure that (PEP) their stock room has order. I am frustrated, disappointed infact disgusted by this. Most people would take those extra items without asking any explanation... Consider other people and their socio economic background. You want to add presure on people because of sales?, or your stock room that has no order at all.