Adam,
I have always been able to correct the problem that you described by adjusting the limit switch. Are you sure that you were on the right limit switch and turning it the right direction? If so, a call to Girard is needed.
Sometimes the awning fabric will stretch and the awning will close on the end both not totally close in the center. or the problem can be reversed were it is tight in the center and loose on the ends. In this case, you need to build the roller tube up a little in the loose area with several layers of something like duct tape to make it close evenly.
Gerald