Mining on testnet

Question

I'm trying to obtain some coins in testnet, so I started monerod, waited until it sync and started mining.

I've got such messages:

2018-04-11 14:31:43.803 [RPC0]  WARN    miner   src/cryptonote_basic/miner.cpp:323      Mining has started with 1 threads, good luck!
2018-04-11 14:31:43.805 [miner 0]       INFO    global  src/cryptonote_basic/miner.cpp:434      Miner thread was started [0]
2018-04-11 14:32:01.349 [miner 0]       INFO    global  src/cryptonote_basic/miner.cpp:488      ←[1;32mFound block for difficulty: 44307←[0m
2018-04-11 14:38:12.748 [miner 0]       INFO    global  src/cryptonote_basic/miner.cpp:488      ←[1;32mFound block for difficulty: 44563←[0m
2018-04-11 14:50:58.558 [miner 0]       INFO    global  src/cryptonote_basic/miner.cpp:488      ←[1;32mFound block for difficulty: 44850←[0m
2018-04-11 15:25:10.985 [miner 0]       INFO    global  src/cryptonote_basic/miner.cpp:488      ←[1;32mFound block for difficulty: 44800←[0m
2018-04-11 15:26:50.575 [miner 0]       INFO    global  src/cryptonote_basic/miner.cpp:488      ←[1;32mFound block for difficulty: 44788←[0m
2018-04-11 15:32:01.486 [miner 0]       INFO    global  src/cryptonote_basic/miner.cpp:488      ←[1;32mFound block for difficulty: 44840←[0m

(and so on)

Am I right that such messages say that I mined some blocks? My balance (both locked and unlocked) is still 0, even after 3 hours passed.

I tried to start mining thread in two ways:

1. monerod.exe --testnet --start-mining 9yE4fY9hpVJayU8hbuigzJVTt3Brhmt9NQXPpZWFjis3EPnoX4D1JTGde6WFMYZcRFNqVdLgQk3FPcFmJComAgfxBGrNfBm It produced several "Found block for difficulty" messages, but balance didn't want to move from 0. I began to worry that I had the wrong address.
2. So I restarted daemon without --start-mining flag, launched monero-wallet-gui, opened my wallet file (with that address), connected it to my daemon and started mining thread from there.

Unfortunately, I didn't get any result.

So, what am I doing wrong and how test coins can be obtained?)