Without more details from you, it's difficult to determine the cause, but an "educated guess" would be that you didn't realize that there are two different passwords that need to be set up.
When you establish an account with Callcentric, just like any website, you entered an account username and account password. Those are only used to access your account on their website.
When you want to set up a SIP endpoint (either a software phone or an ATA or an IP phone), you also need to create a set of SIP credentials. The SIP username is your 1777xxxxxxx account number. You need to manually assign a SIP password for each "extension" you want to use. Enter the 1777xxxxxxx username and SIP password on the OBiTALK website for Callcentric.
Use the OBiTALK web portal to set up your OBi device, not the device's internal webpage (192.168.x.x or 10.0.x.x).
On the OBiTALK web portal, click the SPx you want to set up. On the next page, scroll all the way down to the bottom of the page and click the link that says "OBiTALK Compatible Service Providers". On the next page, click on Callcentric. On the credentials page, fill in those two fields, and submit. Done.
