Ah its not a question of letting them.
For example, we had a visit from the rep of a large MTB brand saying that the other shop had dropped their bikes and would we like them, we duly said yes and ordered a significant amount, sold them and all was good. We came to order more to be told that we werent the dealer anymore and the other place had taken them back, they had a small amount in stock just to push us back out ( both the rep and the dealer were to blame in my opinion as the rep used us a leverage to get back in).
We've had a distributor blank us because the other place threatened to close their account (and they have quite a large account),and finally we had a rep call to say he would deal with us but to keep it quiet and only do small orders so as to not incur the wrath of the other mob.
There are a lot of brands that this shop "stock" according to brand websites but the address listed is'nt a shop its an unmarked warehouse on the outskirts that you can't visit.
And i'm not going to name them as I dont want to start a shop fight 🙂