Just starting planning a straightforward extension and have had an architect draw us up outline plans to put into the council.
I've had to go back with a quite a long list of questions and corrections. The plans were quite sloppily done - loads of typos, inconsistencies in the way things like windows and doors are represented.
Some stuff is just plain wrong - the 'existing' plans included some features that should only have been on the 'proposed' plans. And some stuff just doesn't add up (I can't reconcile the plan view with the exterior elevations, unless he is proposing we build a Tardis!).
I don't know whether to give him a second chance or cut our loses and start again.
I would change too, they could make it better but you will have to check everything, what you want is someone trudstworthy. But tell him why, so he has a chance to do things better for the next client he has.
Are you sure they are an Architect and not an Architectural technician? An Arictitect should be registered with the Architects Registration board and have given you a written agreement before starting the work. Also they should have Professional Intemnity Insurance, which they should show you before starting.
I would check the above out, and change to some one else who could provide the evidence. it could be very costly to you if things go wrong at any time during the build.
Definitely change. We did a huge extension with an architect who was not sloppy but not innovative. He was a family members relative and we were getting mates rates but it's my biggest regret and wish we'd found a firm who would have pushed the boundaries a little more. Good luck with your project