Roaming in Zone A

Currently travelling  in Thailand. Daily roaming passes activated. Belgian pack included 5 GB of data. My Proximus says that once the roaming  pass is active you can use the data in your pack in the third country as if you are in Belgium. Have only used 1.27MB out of 5GB. However phone blocked because the surfing limit roaming of 0.77 MB has been reached.
Was in the chat for over an hour yesterday without being dealt with by a human being despite being told at the start that the wait time was less than 10 minutes on average. Still no reply from Proximus.
Does anybody know what is happening with these completely contradictory rules for roaming outside the EU?