It happened last year, Oct. I think, when they brought out 20 Meg BB (which I presume you are not on).
They never inform existing customers, unless and until you yourself renew you contract with them. Many ISPs & Telcos do the same.
1999: Freeserve 48K Dial-Up => 2005: Wanadoo 1 Meg BB => 2007: Orange 2 Meg BB => 2008: Orange 8 Meg LLU BB => 2010: Orange 16 Meg LLU BB