Manager is a -hole?

We live in a 2bd unit at an apartment. We're supposed to have 2 parkins but when we signed our lease, the mgr said there wasn't one available at this time but if a tenant moves out she will give us that available parking. It's unfair because some tenants have 2 parking and we don't, plus the mgr herself has 3 pks but I guess for the maintenance guys. Anyway, a tenant has moved out making 2 spots available, I asked her if we can have one of it since she promised and the witch said "no". She also said we signed the lease and agreed to 1 parking...I reminded her that she told us she'll give us one when it is available....she rudely said that the next new tentant will have 2 parkins plus a lower priced rental price than ours.........should I stick a nail in her tires or what?!