Ring your supplier and ask if you are getting the best possible discount .
Last year I doubled my discount doing this and just the other week got another 2% off doing the same (changed to paying by direct debit)

Also, each time I do this the contract period restarts so I get $100 credit off my next bill   

While your at it, ring your mortgage provider and hassle them too ...works for me . In fact, last time they rang me to check if I was happy , I said no and they gave me another bit of a discount