Please honour your 4 months free referral promotion.

Cartrack has a promotion where you refer someone and get 4 months free. I referred my wife, who subsequently signed with Cartrack in mid-April. I have not received my 4 months free and was debited on 30 April. Now I have to phone Cartrack to get what should have been given after the referral. Why ask us for referrals if we have to chase after to you to keep your end of the bargain?