I used to play that game too. When money was especially tight, with my bill date approaching, I'd tell them to put my account on hold. That gives you a week to return (or in my case: watch and return) the discs you have out. Then, once I was flush again, I'd re-enable my account, and they'd send the next batch in one lump.
Although, I never pressed my luck, and only did these things every other month at most.
Pioneer VSX-1018AH-K, PDP-5020FD, DV-79AVi
Axiom M22s, VP150, QS8s
Sony PS3, surround backs