The tenacity of sales reps who LIE in order to get through to someone is deserving of this tactic. Those sales reps give the software sales industry a bad rap.
However, to arbitrarily treat all sales reps this way is a real dick move. It is the real world and sometimes the SHTF. When it does and you need help this instant to keep your business running, you will be happy that you took a few of those sales calls. That way you have the relationships in place to expeditiously solve your problem.