As far as i know nokia care here in the philippines isnt really nokia, like you said, i think its like a licensed service center, only that they were allowed to use "Nokia Care" name. just like the nokia stores here, they are owned and operated by different companies using nokia brand name. i had same experience as you with my n8 before. i had it brought in for warranty repairs in megamall, it took more than a month to be replaced because they said that the customs was so slow in processing and releasing the replacement/parts, to be fair though i had been given their number so i could call them for updates. maybe the number you were texting to is a automated machine that cannot process replies. maybe you should try calling the branch or better yet go there and demand to talk to their manager so that you could clear things up.
btw, for comparison, just this january, i had returned a defective plantronics headset for replacement (to plantronics), also took them more than a month to get the replacement unit, they also said that the reason it took so long was because of customs delays... so maybe what nokia care told me was true. although, plantronics did tell me that it could take more than a month before i could get the replacement, that was the only difference cause nokia never gave me any time frame of replacement then.