Where's my 50gigs?

I took out a Giga20 data contract in December 2015. Excited that I'd b receiving the 50gigs promotion that was valid until the end of December. Going through the month of December I realized there was no 50gigs so I called the call centre and they politely told me that I'd receive it in Jan and Feb 2016 since I had taken the contract out in December. So I waited for January but still nothing. Is there a reason y I did not receive the 50gigs data and if I did not qualify then y did the call centre agent give me a different story??