Hello my name is ***** ***** I will help you with this.
Bottled gas are we referring to?
Then no. Unless its in your Park agreement (even then it could be subject to challenge) then he owner can NOT make you do this.,I suspect he is getting a kick back and this in itself could also be illegal.
But no, you can not be forced to chose one supplier.
Can I clarify anything for you about this today please?