agency then returned it to me with them listed as representing me as a limited agent taking a 2% commission. The seller pays it, but that weakens my offer by over $20,000. Do I have a right to be upset at them right now? 
I've done several deals representing myself but never had a seller's agent pull something like this. 

If I return it and take them and their 2% compensation out, will they sour the seller on the deal?

The market isn't super competitive right now, and this property has been on the market for 4+ months, but I am offering $75k lower than their asking price. Part of that is due to it being a cash offer with quick closing, and the other part was the 3% buyer's agent feet ($33k-ish) that they wouldn't have to pay. 

Thoughts?