Bad Service

I deposited cash into the bookshop's account to purchase stationery and books and they gave me a receipt to use to buy whatever I want but I lost the receipt and tried to get them to make me a new one so I can use the remaining amount and I tried to call and get them to perhaps make me another receipt but they said I should call the head office and then called the office twice and they said they'll see what they can do and now close to 4 months has passed and nothing from them and I really need to buy those books and stationery as well Plus the also know how much of the amount is left I don't know what's making them take so long to just print out another receipt since my reference is just my student number which is simple