YES! Community Unfair Policy's Goose Creek South Carolina

I have just moved into one of the communites but before we signed the lease, we visted the community and office several times with our little dog in tow. We were told that it is a pet friendly community and as we drove through the community we noticed that about half the houses have some sort of fencing. The home we were thinking about renting had no fence so we asked would it be okay to put up a small pen. Nothing that's permanant, not attached to anything, nothing that needs to be dug up. We were told it would be okay. I made a $300 dollar investment and now being threatened with eviction if i do not remove it. I have spoke with an attorney and believe we have a case based on the manager not appling the policy fairly across all tennants. 

I asked why it's not being allowed now and all I get is corporate speak stating it's their "guidelines". I asked just for a small compromise to see if we could resolve this. I asked YES! to come up with some sort of approved fencing for our pets as they do advertise as a pet friendly community. (it's mostly for the middle of the night, when it's freezing outside or raining) I also asked if the could not come up with a type of fenceing that i get to keep my pen until the time that all fenceing is removed. Here's the deal...my dog is 15 years old most likely is not going to make it through the winter. I just need it until then. Is this really too much to ask?