refuses to honour promise

When my one year contract ended I was inundated with calls from salesreps to renew. Lindiwe promised me a free month if I signed up with her. No sooner had I signed the contract I emailed her to ask her to confirm the free month. Since then October, she has had no interest in honoring her agreement with me. I have phoned her and spoken to frontline staff. None of them seem to want me to speak to the sales or branch manager. I have tried by phone and in person.