debugging php and API issue

Small job, and should be a quick fix. just need to debug a duplicates issue that comes up sometimes, where leads taken thru a webform API are duplicated. The webform compares the phone number of the lead against the pipeline deals (a CRM) database, and should not allow duplicate entries. If you've had experience with pipeline deals, or CRM's in general, that would be awesome. Here's the API info to give you an idea of their coding. need this done quickly, a day or two deliverability. [login to view URL]