No receipts are required.
I called Zellers, Walmart and Toysrus, Zellers is by far the most friendly store, Toysrus second. Walmart is really sneaky, they are trying to downplay the recall, refused to answer my direct questions until I really pressed them.
Basically they take back everything sold at their store that was made with BPA, a "voluntary" recall at this point until the ruling from Health Canada comes, so it could change anytime. As far as I know, each store takes back the following brands:
Toysrus: Avent, Dr. Brown, Playtex, Gerber, First Years
Zellers: Avent, Playtex
Walmart: Dr. Brown, Playtex, Gerber (I can't remember if they carry Avent).
BPA only applies to those hard transparent plastic bottles, generally speaking those opaque plastic bottles are safe. Rainbow utensils sold at Ikea are SAFE, they are of recycle code 5, I checked last night.
If you are not sure, call the store before to avoid refusal of refund.