If the promise of the gift card was part of the agreement between you and them in regards to purchasing the phone, you could sue them for "breach of contract" to get the card. Unfortunately, suing is the only way to get the card, and if the company is not local (your county) you will not be able to sue in small claims court but will have to sue in regular county court, where the costs of the lawsuit (filing fee; cost to "serve," or legally deliver, "process," or the court papers, on them) will equal or exceed the $200, even if you act as your own attorney ("pro se") and don't have lawyer costs. Some of those costs (filing fee) you can recover in the lawsuit if you win, but other costs (service) you have to bear yourself. If they are not local, it is very unlikely to be worthwhile suing; but unfortunately, suing is the only way to make them pay.