Do you have any international credit card?

If so, you can set up a call back and a rep can register your international CC.

Yes, I do. The number has been blocked since I was not able to complete the payment, so the rep can not do a call back, unfortunately

What do you mean it has been blocked? 

Is your account/ number suspended due to non- payment?   If so, how long it's been suspended?  

Have you tried dual #277?

Yes, the number is suspended due to non-payment. It has been suspended for approx 48 h

Ok. Then it's not too long ago.

You can try dual #277 during business hours tomorrow to talk to bill department.

If you can't connect with them, then send them a message through FB or Twitter.

I am not able to to call the number since I am suspended

I believe the number is #227 - slip of the pen :)  It should work even if your account is suspended!