Architect refuses to stand by construction drawings

Please help, my architect is driving me crazy, because he refuses to stand by the construction drawings that a former employee drew. This is not a little thing. It involves the front of the house.

When the former employee did the drawings, he failed to take into account the alignment of new dormers with a new bay window. My husband and I missed this too. As a result the builder constructed the bay window opening 18 inches to the left of where is should be. I looks terrible.

We want it changed and our builder submitted a change order. Our architect refuses to take the blame even though he admitted verbally that it was his firm's fault. The folmerHe tells us that we approved the plans and that it's our responsibility. I have to say that the plans have been a problem from day one.

What can I do to get this architect to take responsibility?