How to get multiple avatars in only 1 request using Facebook API - facebook

Question

I developed a method for get (doing http requests) the facebook avatars of my friends and convert each image as Sprite. If I have 5 friends i'm doing 5 requests. It worked some months ago. But now it doesn't work. I receive a 'time out' response when I try to get the second avatar.
I suppose that this problem is related to the quantity of requests that i'm doing. Maybe Facebook has a new 'flood protection'.
So, now, i'm trying to make an only one http request for obtain ALL avatars at the same time. In the official documentation (https://developers.facebook.com/docs/graph-api/making-multiple-requests) I read that I should use "Batch request" but the response that i'm getting doesn't contain the information for construct each image. How can I solve it?
Background:
C++ / cocos2d-x / class network::HttpRequest
network::HttpRequest* req = new network::HttpRequest();
req->setUrl("https://graph.facebook.com");
vector<string> header;
header.emplace_back("User-Agent: MyApp/1.0");
header.emplace_back("Content-Type: application/json");
req->setHeaders(header);
req->setRequestData(requestBody.c_str(), requestBody.length());
req->setRequestType(network::HttpRequest::Type::POST);
network::HttpClient::getInstance()->send(req);
requestBody content:
{
“batch”: [
{
“method”: GET
“relative_url”: http://…url to the direct download to avatar-image
},
{
“method”: GET
“relative_url”: http://…url to the direct download to avatar-image
}
],
“access_token”: “…”
}
(All of the relative_url works because I tested it in a browser)
Example of data response that I'm receiving:
[{
“code”: 200,
“headers”: [{
“name”: “Expires”,
“value”: “Sat, 01 Jan 2000 00:00:00 GMT”
}, {
“name”: “Cache-Control”,
“value”: “private, no-cache, no-store, must-revalidate”
}, {
“name”: “Access-Control-Allow-Origin”,
“value”: “ "
}, {
“name”: “Pragma”,
“value”: “no-cache”
}, {
“name”: “Strict-Transport-Security”,
“value”: “max-age=15552000; preload”
}, {
“name”: “ETag”,
“value”: ““3f2ef278dacb9dfc1c3827404a99ad8dfedc20cd””
}, {
“name”: “Vary”,
“value”: “Accept-Encoding”
}, {
“name”: “X-App-Usage”,
“value”: “{“call_count”:10,“total_cputime”:0,“total_time”:0}”
}, {
“name”: “Content-Type”,
“value”: “text/javascript; charset=UTF-8”
}, {
“name”: “Facebook-API-Version”,
“value”: “v2.12”
}],
“body”: “{“id”:“https://platform-lookaside.fbsbx.com/platform/profilepic”}”
}]
With that response I don't have the information for construct an image-sprite. Example of the responseData that I need for construct 1 sprite-image: \377\330\377\340