I completed the 7 day challenge and did not get the 10 sweet love shards
If you wanted 7 day challenge rewards, you had to redeem those manually. Unfortunately its too late now, as the event is over. However, if you did redeem rewards in time and you didnt get those, I would suggest you to contact live support.
I was doing that and completed 65 achievements to get the shards but as soon as I did it all froze and it disappeared meaning I could not redeem it manually. I read somewhere to wait and they may appear but unfortunately have not hence why I am writing to see if I can get it resolved