Quintum can work pretty well in calling card applications. They just do not offer a billing.
Buy a good billing for prepaid calling cards and Quintum will do wonders.
Also, Quintum are going to release an extended IVR / TCL support till the end of the year.
As regarding to support – Quintum support is very good (if you pay for it).
Of course Cisco (and any other vendor) will ask for tech support.
If you buddy, sell cars, do you sell free repair and maintenance for them? Of course, not.
Welltech – if you really have hard time with it, I can bring it up for you in 10 min.
Contact me at email@example.com.