best buy same as cash

In August of 2006 I purchased a washer and dryer. At the time I was told

that if I opened a Best Buy account I could make monthly payments and if the

account was paid in full within one year, I would owe no interest. I did

this and kept me part of the agreement. Now Best Buy insists I pay them the

interest. I even sent them a copy of the receipt I received stating that

the purchase was a "same as cash" purchase. They will not give me a good

explanation other than the receipt is not correct. I will never purchase

another item from this company.