Refusing to correct their error on a personalised item

I order a (very expensive) personalised item to state "the Mundeys" as advertised on Netflorist. The order page just requested that the family name be completed, so I typed in "Mundey". When I received my order they had printed "the Mundey". They had by default included the prefix "the" but not added an "s" onto the end of the family name as advertised. This is very inconsistent and it does not make sense to have an item that is labelled "the Mundey" as a bulk family branded item. I addressed this with Netflorist and they rep**** that they will not correct the order! I then pleaded my case further and after not receiving feedback I asked for it to be escalated, yet still no reply. Disgusting customer service and definitely one way to lose business.