What do I do if the urn is too small for the cremation ashes?

I decided to order a custom-made cremation urn in the shape of a heart for my wife's ashes after she passed. Unforuntately when it arrived I saw that the urn is far too small to hold all her ashes. I love the personalized urn I chose for her and really want to use it. However, I don't know what to do with the rest of the ashes that don't fit in it. Should I find a second urn for the remainder of her ashes, or just buy a bigger urn to hold all of them? I appreciate the help.