Why does Siebel reject this phone number " 541145522711/21/24 INT.: 24" with the error "Can't conver

Why does Siebel reject this phone number "+541145522711/21/24 INT.: 24" with the error "Can't convert formatted string to its internal representation"?  I thought a plus sign preceding the phone number allowed any format.  I even tried updating the PHONE_FORMAT list of values by changing 54 to 0 in the Order column, and Siebel still rejects it.  The person who wants to store this phone number in Siebel says it is a valid phone number.  His explanation is as follows:

+54for country

114 for city

5522711 Number

Alternative number ending /21/24

Extension: INT.: 24