Victoria has a 4hr/peak sun equivalent/ day just as I have.
Peak Sun Hours Canada: (List, and Maps) – Dot Watts®
All things being ideal and perfect you have a potential of 5.7KW x 4h x 30 (days)= 684KWH/month. That times the rates you provided calculates to (14KWH x .10 + 670KWH x .049) = $34.23/month.
You put them on a north facing roof which reduces potential about 30% and east which reduces potential 15%. If these numbers are correct, you at absolute best could expect a savings of about $20/month. That's not even considering snow loss or voltage management. Is maybe the credit a cumulative figure? Some companies here bank your credits monthly, others quarterly, others annually (best). My state has a ridiculous number of independent power companies (about 300) each makes it's own rules within some very basic State guidelines.
I'm editing my post because I just noticed your billing is quarterly (90 days) that makes much more sense. You also must be getting more per KWH than you think. You still stole the system at $5700!. Good for you.