Check out this link from the developer's official website: https://www.ibm.com/planetwide/us/#techsup
There are several phone number written there; pick the one that best describes your problem/inquiry. Additionally, you will also find a few contact emails, in case the phone solution doesn't work as intended.
In case you're not from the U.S., at the bottom of the page, you will see a drop-down menu that allows you to choose your region/country. Pick your location, wait for the page redirect, then go to the support section and you will find out how to contact the local branch of the company or a local partner.
