Be warned that mixing different formulations of toner could cause the toner to not stick tot he drum properly and start to pool up in your printer requiring expensive maintenance.
Lets put aside the fact that you wouldn't know the correct values for whatever garbage generic toner the refill company gave you. How are you going to deal with the fact that the printer already has particles of the old toner in the system and now you are introducing contamination with a set of different particles from the new cartridge/refill?
You might also need to adjust the fuser temperature for non-oem toners