Well, that's definitely worse than just a "snug fit" ! And it certainly sounds like it needs something more than someone playing around with a bottle jack to get it right.
Can you tell if there is a specific point where it's binding up? (i.e. near the upper pin, the lower slot, at some point along the bracket itself, etc.) Again, this is what your dealer should be doing, but it sounds like you may have to grab him by his ear (or something else !) and lead him around. The
B2920 with BH65 is a pretty popular package. I expect there are several TBN regulars who own them and many other owners who also read and post here. If this were a common problem, it's likely word would have gone out long before this.
One possibility is that, since backhoes are installed at the dealer's, something in the installation was misaligned or bent, causing your problem. The dealer may be trying to avoid 'fessing up if that's the case, and that's why you seem to be getting the run-around.
Regardless of why, that is completely unacceptable. You paid a very tidy sum of money for what should be a top-notch product and it is essentially unuseable for the work you bought it to do.
I would suggest the following course of action. First, arrange a meeting with the
owner of the dealership, not the mechanic, sales manager or anyone else. Explain to him that your very expensive new tractor cannot be used as intended because of the backhoe mounting problem. Tell him the sequence of contacts and attempted repairs. Tell him he has one week to either fix it correctly or provide you with a replacement that is working properly. Tell him your next contact will be with Kubota directly.
If the owner is who you have been dealing with all along, and he can't or won't make things right, your best bet is the Kubota regional rep. Kubota is a company that takes their reputation for good equipment very seriously and seems to try very hard to keep their customers happy, even if a dealer sometimes goes astray.
Again, good luck and I hope they step up and treat you right.