Bottled spice mixes for Desi dishes

Hi guys … anyone used those bottled spice mixes that are available in ASDA and Tesco?

you know, the ones like Jalfrezi Mix , Korma or Chicken Balti etc … I used them once or twice and felt they were totally horrid and too sweet … actually I could also feel the taste of the preservatives :no:

I am thinking , perhaps i dont know how best to use them … so anyone here wants to share their experience?