I guess we are talking about tetra easy balance here... I know that usually employees from the pet stores want to sell us as much products as possible, but this one is totally useless. Why to add so much chemicals instead of keeping the water clean and warm?
Please provide more info:
http://www.bettafish.com/showthread.php?t=49233
For the moment, you should do a 100% water change and add some stress coat as a conditioner. In the case you don't have stress coat and you don't have the possibility to get it, use the aqua safe. (I guess were talking about tetra aqua safe). In this new water add only one conditioner, Stress Coat (or Aquasafe). Stop using Easy Balance and Bettafix. The conditioner should be used according to the instructions listed on the bottle, not more, nor less. Please make sure you acclimatize your betta properly before you release him in the new water. This is extremely important. LittleBlueFishlets explained you how to do it.
Can you please add a photo of him to see the fins?