Based on Andrew's description" when pressed, has some blinking lines in a circle, then displays 888888 (with the dot in the lower right and all lines on the left displayed), and then "502001".", it is highly possible that the token cannot get the seed/secret information (we'd better not let the customer know this), there are two possible causes: 

1) The token was not programmed with any seed during the production.

2) The token had the seed after production, but somehow lost it.

For cause 1, in theory our factory can find that kind of tokens in their factor inspection process, but still we need to ask customer if that token could not work the first when he used it or it worked normally before. 

For cause 2, we had a few similar reports before, we did not find the root cause since this should not be a hardware issue but firmware issue, and we've upgraded the firmware to add some extra protection. Since the token worked before, we need to know if the customer can recall whether there was some environment changes (such as, the token was suddenly dropped on the ground, token was in too high/low temperature, etc.) 

As for sending that token back, for us this is not mandatory, but if it will not cause much trouble to customer and to you, please send it back to Beijing.