unable to sim unlock

Hi,

I am trying to sim unlock my phone (prepaid service) and I am eligible to do it (I have my phone since Feb. 22) but when I am trying to do the unlock request, the website says "Error: We found no record of the IMEI Number you entered. Check your device's 15-digit IMEI Number by dialing *#06# (errorCode.ULP2003)": I have tried it a lot of time (thus it is not a mistake in the IMEI given). As I am in europe with my gophone (and won't come back in the us before a long time), I am not able to contact the support service.

What should I do?

Thank you in advance.

Best,

Loic