Since they were advertised as new, I would return them. You should def get a full refund because they are false advertisement. Try to call the place you ordered them from and tell them your concerns. A new pair of shoes should not have the serial number blacked out! I would def demand a full refund, plus a refund for the shipping. Threaten to report them to the BBB if they say they will not refund you your money.

Personally, I wouldn't give them as a gift if they are not in the condition you expected them to be in.