walmart money center/money gram

I purchased several money orders at customer service department of walmart located in oceanside ca on vista way. 3 of this money orders was returned to me by the company money orders was paid to for simple reason that payment they requested was covered by other money orders. So 3 of them just was not used. Walmart refused to pay me back saying that i should file a claim to the moneygram who charging $15 fees for every money order for refund. ridiculous ! never again. Any other location may be charge mor than 60 cents per order but they do eazy refunds with no extra fees.