Steeping flaked oats, flaked wheat or crystal malt will NOT contribute any fermentable sugars unless some 'base' grain such as pale, pilsner, munich malt, etc. is present to enzymatically convert the starches to fermentable sugars. You will get some haze from the oats and maybe a little mouthfeel, but no fermentable sugars.
Regarding your OG, I agree, you should have been above 1.050. Kinda hard to miss your OG with extract. Basic question that always gets asked when this comes up from new brewers: how vigorously did you stir before you took your sample? In other words, is there a chance that your sample was a bit watery since your wort was not sufficiently mixed? Just a thought. Either way, your beer will be drinkable.
Lastly, even though this is not a classic wit, making this type of beer and/or wits was THE primary reason I went all grain. I am convinced that you simply cannot make a Blue Moon or (and I know I am stretching since the beer in this thread is not a wit in the classic sense) a Hoegaarden with extract or with extract and grains. I couldn't and I tried my hardest over a couple years. My first AG was a wit and after that, there was no going back.