Problem with unlocking a device associated with AT & T

Hello, good morning, my name is Manuel Ortega I am from Venezuela and I bought an iphone 4s phone on ebay last week, the phone in a very excellent condition. The problem lies in when I put a sim in the country, which will not stop. activate, find out a bit on the internet and I saw that there was a way to contact the telephone service to which this device was apparently associated, I could place the unblocking request, in 1 day, they answered:

'' We can not approve your unlock request

Based on your device purchase date your service has not been active for at least 60 days.

Device IMEI number: 013182009719874
Request number: NUL322860766022
 
Hi MANUEL,
 
Submit a new request in more than 60 days from your device purchase date. ''

the detail is that the person assures me that the device when it was bought until last month that I bought it and I arrived last week if it fulfilled with more than 60 days activated ... I mean that it fulfilled surplus with the payment of the cel .. And well I have seen several cases in forums of this type where unfairly or in favor of the company end up harming its users.

In my specific case, it is impossible for me to communicate personally with one of its branches because I am from the other side of the world. What options does a person like me have to solve this problem?

Thank you very much in advance, I would like a solution that is convenient both to you as a company that is respected and to me as a user of a telephone.

Excuse me my English grief.