I got the same call in August, but I took up the offer.

Basically, if you are not planning to relocate, and that you are happy with the service & no plans to switch, it is a good deal and you can have the next higher speed for RM30 discount for lifetime! Heard that recently no such offer anymore, but you will only get RM20 discount, or pay the full amount + HyppTV package (not sure which one) for free.